NJW4120

- 1 -

Ver.2005-03-09

Lithium-ion Battery Charger Controller IC with Timer

GENERAL DESCRIPTION

PACKAGE OUTLINE

FEATURES

Charge Control Feedback by Photocoupler
Adjustable Charge Voltage

Adjustable Pre-Charge and Full Charge Current
Temperature Monitor
Over Charge Timer
Internal Re-Charge function
Delay timers and Hysteresis inputs for high noise immunity
Over Discharge Battery Detect
Over Voltage Protection
Bi-CMOS Technology

Package Outline

NJW4120M : DMP20
NJW4120V :

SSOP20

PIN CONFIGURATION

NJW4120 is a 1-cell and 2-cell lithium ion battery charge control IC
with a built-in AC-DC secondary side control feature. Using a
photocoupler to directly feed back optimum charging voltage and
current information to the primary side, it increases energy
efficiency, makes possible a smaller charger, and conserves
energy. Charging current can be freely set and therefore it is
possible to optimize charging according to battery capacity.
As safety features it has over voltage, over discharge, temperature
detection, and a charge over timer. Also, the adaptor and the
charge control circuit are mounted on one chip.

NJW4120M NJW4120V

P-CHG

NFB

TX-SW

GND

ADP

LED-G

LED-R

CHG-SW

TDET

VREF

CS2

CS1

Q-CHG

NJW4120M
NJW4120V

NJW4120

- 2 -

Ver.2005-03-09

ABSOLUTE MAXIMUM RATINGS (Ta=25°C)

PARAMETER SYMBOL

MAXIMUM

RATINGS

UNIT

Operating Voltage

+15 V

C1 Pin Voltage

+5 V

C2 Pin Voltage

+5 V

TDET Pin Voltage

TDET

+5 V

TX-SW Pin Output Current

SINK-SW

50 mA

PC Pin Output Current

SINK-PC

50 mA

LED-G Pin Output Current

SINK-G

20 mA

LED-R Pin Output Current

SINK-R

20 mA

Power Dissipation

DMP20 :300

SSOP20 :300

Operating Temperature Range

opr

-20~+85

Storage Temperature Range

stg

-40~+125

ELECTRICAL CHARACTERISTICS (V

=5V, Ta=25

PARAMETER SYMBOL TEST

CONDITION MIN.

TYP.

MAX.

UNIT

General Characteristics

Operating Voltage

2.7 14 V

Operating Current

CHG-SW:

OPEN

2 3

Under Voltage Lockout Block

ON Threshold Voltage

T-ON

2.2 2.4 2.6 V

OFF Threshold Voltage

T-OFF

2.0 2.2 2.4 V

Hysteresis Voltage

HYS

100 200 300 mV

Reference Voltage Block

Reference Voltage

REF

=0mA 1.228

1.24

1.253

Load Regulation

REF

=0mA~1mA

Voltage Detection Block

Quick Charge Detection Voltage

Q-CHG

VS: L

BAT

x 0.71

BAT

x 0.73

BAT

x 0.75

Re-Charge Detection Voltage

R-CHG

VS: H

BAT

x 0.94

BAT

x 0.95

BAT

x 0.96

Over Voltage Detection Voltage

VS: L

BAT

x 1.015

BAT

x 1.025

BAT

x 1.035

Charge Control Block
Reference Voltage

REF-CV

2.08 2.1 2.12 V

Adaptor Control Block
Reference Voltage

REF-ADP

1.228 1.24 1.253

VS Pin Input Bias Current

VS=2.1V

50 500 nA

Battery Connected
Detection Voltage

T-TDET

TDET

1.15

Low Voltage Detection (2mA Charge) Block

Charge Current

CHG1

VS=1V

1 2 3

Low Voltage Detection Voltage

VS: L

BAT

x 0.505

BAT

x 0.525

BAT

x 0.545

NJW4120

- 3 -

Ver.2005-03-09

ELECTRICAL CHARACTERISTICS (V

=5V, Ta=25

PARAMETER SYMBOL TEST

CONDITION MIN.

TYP.

MAX.

UNIT

Current Detection Block

Pre-Charge /Quick Charge Block
Voltage Gain

CS1=3.8V,

CS2=3.6V

11.5 12 12.5 dB

Full Charge Detection Voltage

CS2=4.2V,

VS=2.1V

8 12 16 mV

CS1 Pin Input Bias Current

CS1

CS1=4.2V

10 500 nA

CS2 Pin Input Bias Current

CS2

CS2=4.2V

10 500 nA

Photocoupler Out Block

Photocoupler Out
Saturation Voltage

OL-PC

SINK

=20mA

0.2

0.5

PC Pin Leak Current

LEAK-PC

=14V

TX-SW Out Block

TX-SW Out Saturation Voltage

OL-SW

SINK

=20mA

0.2

0.5

TX-SW Pin Leak Current

LEAK-SW

=14V

LED Out Block

LED-G Pin Saturation Voltage

OL-G

SINK

=10mA

0.2

0.5

LED-G Pin Leak Current

LEAK-G

=14V

LED-R Pin Saturation Voltage

OL-R

SINK

=10mA

0.2

0.5

LED-R Pin Leak Current

LEAK-R

=14V

Timer Block

OSC1 Timer Error Time

T1 -10

+10

OSC2 Timer Error Time

C1=C2=0.01

F external

Not including external deviation

-10 +10 %

CHG-SW Block

ON Threshold Voltage

SW-ON

0.25 V

OFF Threshold Voltage

SW-OFF

Pull-up Resistance

PULL-UP

300 500 700 k

NJW4120

- 4 -

Ver.2005-03-09

TYPICAL APPLICATION

Reference

Voltage 1

1.24V

Reference

Voltage 2

2.1V

REF1

REF2

OSC

Full
Charge
Timer

Pre-
Charge
Timer

CLK

Control
Logic

Start/Stop

Time Out

Low Voltage
Detection

Over Voltage
Detection

Re-Charge

Quick Charge

Full Charge

Detection

6dB

CVCC-ON

REF2

12dB

r
e-

har

Contr

o
l

u
i
c
k
C

Contr

o
l

CVCC-ON

Start/Stop

Time Out

BAT

x 1.025

Charge

-ON

BAT

x 0.525

BAT

x 0.95

BAT

x 0.73

Quick/

Pre-Charge

CVCC-ON

CS1 pin

2mA

Charge

ON/OFF

Battery

Voltage

Detection

Q-CHG

P-CHG

REF

NFB

CS1

Rcs

CS2

TX-SW

GND

REF

Input

GND

CVCC-ON

REF1

CVCC-ON

ADP

1-cell:

= R

2-cell:

= 3xR

Adaptor Output

LED-G

LED-R

LED-G

LED-R

PULL-UP

CHG-SW

Low Temperature
Detection

High Temperature
Detection

Battery Connected
Detection

UVLO

TDET

TH

TL

Lithium Ion Battery

REF

NJW4120

- 5 -

Ver.2005-03-09

PIN CONFIGULATION

Pin No.

Pin Name

Function

P-CHG

Pre-Charge Current Setting

2 NFB

Current-Regulation-Loop

Compensation

3 TX-SW

Switch

Transistor

connection

4 GND

GND

Photocoupler connection for the first side feedback

ADP

Adaptor Control Voltage Setting

7 LED-G

LED

Output

8 LED-R

LED

Output

Pre-Charge Timer, 2mA Charge Timer, LED Blinking Cycle, Delay Time Setting

10 C2

Quick

Timer

Setting

CHG-SW

Charge ON/OFF Control

Batteries Thermal (High Temperature) Setting

Batteries Thermal (Low Temperature) Setting

TDET

Battery Temperature Detection, Battery Connected Detection

15 V

Operating

Voltage

16 VREF

Reference

Voltage

Output

Battery Voltage Detection

CS2

Charge Current Detection 2

CS1

Charge Current Detection 1

Q-CHG

Quick Charge Current Setting

CHARGE VOLTAGE / CURRENT for RESISTANCE SETTING

Parameter

Calculation formula

Examples of calculation

Adaptor Output Voltage

ADP

x V

REF-ADP (1.24V)

5.0V 10V

Charge Control Voltage

BAT

x V

REF-CV (2.1V)

4.2V 8.4V

Low Voltage Detection

Voltage

BAT

x 0.525

2.21V

4.41V

Quick Charge Start Voltage

BAT

x 0.73

3.07 V

6.13 V

Re-Charge Detection Voltage

BAT

x 0.95

3.99 V

7.98 V

Over Voltage Detection

Voltage

BAT

x 1.025

4.305 V

8.61 V

Pre-Charge Current

P-CHG

= (

x V

REF (1.24V)

/ 4) / R

(at. R

:232k, R

:16k, R

=0.2)

100mA

Quick Charge Current

Q-CHG

= (

x V

REF (1.24V)

/ 4) / R

(at. R

:128k, R

:120k, R

=0.2)

750mA

Full Charge Current

F-CHG

= (96mV / 8) / R

(at. R

=0.2)

60mA

NJW4120

- 6 -

Ver.2005-03-09

TYPICAL CHARACTERISTICS

2.08

2.09

2.1

2.11

2.12

-50

-25

100 125

Ambient Temperature Ta (

f
e
r
e
nc

e
Vo

l
t
ag

-
C

)

Charge Control Block Reference Voltage

v.s Temperature (V

=5V, VS Pin)

1.23

1.235

1.24

1.245

1.25

-50

-25

100 125

Ambient Temperature

Ta (

t
o
r

C

o
n
t
r
o
l
Bl

k
Re

f
e
r
e
nc

e V

o
l
t
a
g
e

-
A

)

Adoptor Control Block Reference Voltage

vs. Temperature (V

=5V)

1.23

1.235

1.24

1.245

1.25

-50

-25

100 125

Ambient Temperature

Ta (

e
fer

enc

e V

o
l
t
ag

)

Reference Voltage vs. Temperature

=5V, I

REF

=0mA)

11.4

11.6

11.8

12.2

12.4

12.6

-50

-25

100 125

Ambient Temperature

Ta (

r
e-

h
a
r
ge

u
i
c
k
Ch

o
c
k

o
l
t
ag

e G

a
i
n

(dB

)

Pre-Charge/Quick Charge Block Voltage Gain

vs. Temperature (V

=5V, CS1=3.8V, CS2=3.6V)

0.2

0.3

0.4

0.5

0.6

0.7

0.8

-50

-25

100 125

Ambient Temperature

Ta (

h
r
e
s
h

d
Vo

l
t
ag

(

)

CHG-SW Block Threshold Voltage

vs. Temperature (V

=5V)

SW_OFF

SW_ON

0.5

1.5

2.5

-50

-25

100 125

Ambient Temperature

Ta (

p
er

a
t
i
n
g
C

r
r
en

t

I

)

Operating Current vs. Temperature

=5V, CHG-SW:OPEN)

NJW4120

- 7 -

Ver.2005-03-09

TYPICAL CHARACTERISTICS

0.1

0.2

0.3

0.4

0.5

TX-SW

t
u

r
a

t
i
o

n
Vo

l
t
a

-
C

)

TX-SW,PC Pin Saturation Voltage vs. Sink Current

=5V, Ta=25

Sink Current I

SINK

(mA)

0.1

0.2

0.3

0.4

0.5

a
tur

a
ti
on

o
l
t
a
g
e

V

)

LED Pin Saturation Voltage vs. Sink Current

=5V, Ta=25

Sink Current I

SINK

(mA)

LED-R

LED-G

100

0.001

0.01

0.1

s
c
i
l
l
a
t
i
on C

y
c
l
e

,

OS

2

(
m

s
)

Oscillation Cycle vs. Capacitance

=5V, Ta=25

Capacitance C1, C2 (

-50

-25

100 125

Ambient Temperature

Ta (

c
i
ll
a
t
io

n
C

y
c
l
e

,

O

2

(
m

s
)

Oscillation Cycle vs. Temperature

=5V, C1=C2=0.01

NJW4120

- 8 -

Ver.2005-03-09

Feature Description

1. Photocoupler Feedback Unit (PC pin, CHG-SW pin, TX-SW pin)

NJW4120 feeds back voltage and current information that are required for battery charging via a photocoupler to the
primary side of the AC/DC converter, and controls AC/DC converter output. No special method is required if the
primary side of the AC/DC converter that is being controlled (whether self excited or externally excited) has circuitry
that takes into account the range of output voltage and current that is required for charge control.
It also incorporates an adaptor output mode, and extraction of any constant voltage output is possible. The following
will switch between charge control and adaptor output.

CHG-SW pin, and TDET pin battery set detection are both on: Charge control mode
Either CHG-SW pin, or TDET pin battery set detection is off: Adaptor output mode

However, if charging is prohibited due to over voltage detection, temperature detection, or the charge over timer, or
when there is 2mA of charge, the system will move to adaptor mode.

The unit that controls feedback to the photocoupler consists of the ADP voltage control, charge voltage control, and
charge current control amps. Each amp controls the photocoupler drive transistor via an OR circuit (Figure 1).

To VS pin

Adaptor output

PC ADP

NFB

CVCC-ON

To P-CHG pin

To Q-CHG pin

To current detection
12dB amp

REF1

(1.24V)

Pre/Quick charge switch

REF2

(2.1V)

To AC/DC converter
primary side control

ADP voltage

control

Charge Current control

Charge voltage control

TX-SW

CVCC-ON

SW transistor

Figure 1 : Photocoupler Feedback Unit and SW Transistor

NJW4120

- 9 -

Ver.2005-03-09

Feature Description

(Continued)

Amp control and control of the SW transistor connected to the TX-SW pin are not the same in adapter output mode
and charge control mode.

1-1. Adapter output mode (ADP pin)

In adapter output mode, each of the circuits in the control unit will be in the following state.

ADP voltage control amp

Charge voltage control amp

OFF

Charge current control amp

OFF

transistor

OFF

To set the adapter output voltage, use the ADP pin's external resistors R

, and R

and the following formula.

ADP

x V

REF-ADP (1.24V)

In adapter output mode the SW transistor connected to the TX-SW pin will turn OFF, and charge to the battery will
be cut off. For this reason, take adapter output voltage from a power supply line that comes before the SW transistor.

1-2.Charge control mode

In the case of pre-charge and quick charge each of the circuits in the control unit will be in the following state.

ADP voltage control amp

OFF

Charge voltage control amp

Charge current control amp

transistor

However, when there is 2mA of charge, the system will operate in adapter output mode (SW transistor

OFF).

The SW transistor turns ON, and battery charging will be performed.
Charge voltage and charge current operations are described in "2. Voltage Detection Block", and "3. Current
Detection Block".

NJW4120

- 10 -

Ver.2005-03-09

2. Voltage Detection Block (VS pin)

The VS pin determines charge voltage, low voltage, over voltage, and re-charge voltage. Battery voltage conditions are
constantly monitored. (Figure 2)

2-1. Charge Voltage (VS pin)

Charge voltage V

BAT

is set using the VS pin external

resistors R

and R

and the following equation:

BAT

x V

REF-CV (2.1V)

Using the following settings makes it easy to support
applications for one or two cells: for one cell, R

= R

;

for two cells, R

=3 x R

If you use a high resistance, the VS pin's bias current will
cause incorrect values. Use as low a resistance as
possible.

2-2. Overcharge Detection Block (VS pin)

The overcharge detection block stops charging when a
high voltage is detected at the VS pin.
The overcharge detection voltage is obtained with the following equation:

BAT

1.025 (typ.)

When overcharge is detected, charging is prohibited and LED-R blinks. After that, charge will continue to be prohibited, even
after battery voltage drops to a normal value. Turning the power off to release UVLO, battery connection detection, or
CHG-SW switching will enable the charge sequence to restart.

2-3. Low Voltage Detection (2mA charge) Block (VS pin, CS1 pin)

The low voltage detection block detects an
over-discharged battery, or an open battery caused by
the battery protection circuit or the like. This will
determine a 2mA charge prior to pre-charging.
The low voltage detection voltage is obtained with the
following equation:

BAT

0.525 (typ.)

During a 2mA charge, the block monitors battery voltage
recovery while a steady 2mA current is output from the
CS1 pin. (Figure 3)
If voltage does not recover within a prescribed time, the
timer will prohibit 2mA charging. Turning the power off to
release UVLO, battery connection detection, or CHG-SW
switching will enable the charge sequence to restart.

2-4. Re-Charge Detection (VS pin)

When a fully charged battery is left for a long period of time, voltage will drop due to self-discharge. The re-charge detection
block detects a drop in voltage and re-charges the battery.
The re-charge detection voltage is obtained with the following equation.

R-CHG

BAT

0.95 (typ.)

Low Voltage
Detection

12dB

CS1

Rcs

CS2

To Charge
Output

Control Block

2mA Charge
Current

To Charge Current
Control Amp

2mA Charge

BAT

x 0.525

To Charge

Control Block

To OR
Circuit

Charge Voltage
Control Amp

REF2

CVCC-ON

Low Voltage
Detection

Over Voltage
Detection

Recharge
Detection

Quick Charge
Detection

Battery
Voltage
Detection

1-cell

= R

2-cell

= 3xR

BAT

x 0.95

BAT

x 0.73

BAT

x 1.025

BAT

x 0.525

Figure 2. Voltage Detection Block Configuration

Figure 3. 2mA Charging Block

NJW4120

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Ver.2005-03-09

FEATURE DESCRIPTION (CONTINUED)

3. Current Detection Block (CS1 pin, CS2 pin)

A current detection resistor R

is inserted between pin CS1 and pin CS2 to monitor battery charge current.

The input voltage between pin CS1 and pin CS2 is amplified by the 12dB current detection amp and fed back to the charge
current control amp. (Figure 4)

3-1. Pre-Charge Current, Quick Charge Current (P-CHG pin, Q-CHG pin)

This will switch between charging with pre-charge current or quick charge current according to the level of the battery
voltage V

BAT

that is input from the VS pin.

BAT

x 0.525 to V

BAT

x 0.73

Pre-charge control

BAT

x 0.73 to V

BAT

Quick charge control

Pre-charge and quick charge current values are determined by the P-CHG pin and the Q-CHG pin voltage settings.
Settings are made according to the following formulae.

Pre-Charge Current Value

P-CHG

= (

x V

REF (1.24V)

/ 4) / R

Quick Charge Current Value

Q-CHG

= (

x V

REF (1.24V)

/ 4) / R

3-2. Full Charge Detection (F-CHG pin)

Charge termination is determined by a set full
charge current

F-CHG

, which is determined by a

voltage setting on the F-CHG pin.

F-CHG

= (96mV/ 8) / R

When charging is terminated, LED-G turns on,
and the sequence moves to the re-charge
detection operation.

Figure 4. Block for Controlling Pre-Charge, Quick Charge,

and Block for Detecting Full Charge.

To OR
Circuit

Quick Charge
Detection

Full Charge
Detection

6dB

CVCC-ON

12dB

e
-
C

h
ar

r
r
ent

Set

t
i
n
g

u
i
ck C

r
g

r
r
ent

Set

t
i
n
g

Quick/
Pre-Charge

Q-CHG

P-CHG

REF

CS2

NFB

CS1

Rcs

CS2

To Charge
Output

Switch Pre/Quick
Charge Current

Control Block

To Charge Voltage
Control Amp

Charge Current
Control Amp

BAT

x 0.73

NJW4120

- 12 -

Ver.2005-03-09

FEATURE DESCRIPTION (CONTINUED)

4. Temperature Detection Block, Battery Connected Detection Block (TDET pin, TH pin, TL pin)

The charge temperature range is set with the TL pin (high temperature) and the TH pin (low temperature).
The threshold voltage for the temperature detection comparator is set with the external resistors R

THL

, R

. Therefore,

you can select any type of thermistor (NTC) and any charge temperature range (Figure 5).

The TL pin and the TH pin are set to go to the potential states shown below for fluctuations in TDET voltage.
V

(high temperature) < V

TDET

(charge Temperature) < V

(low temperature)

Pin voltages are obtained from the
following formulae.

TDET pin (thermistor setting)

)

(

REF

TDET

TH pin (low temperature setting)

)

(

REF

THL

TL pin (high temperature setting)

)

(

REF

THL

Figure 5 Temperature Detection Block

When the detected temperature goes out of the range of the set values, charging stops, and LED-R and LED-G turn off.
After temperature is restored, charging recommences in line with battery voltage status.

The TDET pin is also used for the battery-connected detection feature.

The battery-connected detection feature determines that a battery is connected if TDET pin voltage is no greater than
1.15V(typ.), and commences charging.

Battery Connected
Detection

Low Temperature
Detection

High Temperature
Detection

Charge

-ON

TDET

TH

TL

Lithium Ion Battery

REF

To CHG-SW

THL

TDET

To UVLO

T-TDET

=1.15V

NJW4120

- 13 -

Ver.2005-03-09

FEATURE DESCRIPTION (CONTINUED)

5. Delay Circuits (each detection block)

Each detection block has a delay circuit and extra features for preventing malfunction due to noise or excess signals.

Table 1 Delay Circuits and Extra Features.

Detection Block

Delay Circuit

Extra Feature

Low Voltage Malfunction
Prevention Circuit

Hysteresis

CHG-SW Hysteresis
Battery Connected
Detection

Hysteresis

Temperature Detection

Hysteresis

Full Charge Detection

Re-Charge Detection

Low Voltage Detection

Hysteresis

Over Voltage Detection

Delay I

Latch

Quick Charge Detection

Delay II

Hysteresis

The delay circuit block receives a signal from the timer circuit to fix a delay time.
For details on the relationship between the delay time and capacitors see "6. Timer Circuit Block".

6. Timer Circuit Block (C1 pin, C2 pin)

OSC1 is used for the timer that is used for pre-charge, 2mA charge and the like. OSC2 is used for the quick charge timer.
You can change the time of the timers with external capacitors. Tables 2, 3 show the relationship between capacitance and
time.

Table 2 C1, C2 Oscillation Cycle t

Capacitance (C1, C2)

Oscillation Cycle

(OSC1, OSC2)

4700pF t

4.7ms

0.01

t = 10ms

0.022

t = 22ms

0.047

t = 47ms

Table 3 Timer Time

Use capacitors the have good temperature characteristics in the OSC block.
Capacitor deviation will cause timer errors.

Block Name

Parameter

Calculation

Formula

Examples

2mA Charge Timer

tx2

10.2s

Pre-Charge Timer

tx2

22min.

LED R Blinking Cycle

tx2

1.28s

Delay I

tx2

0.32s

Pre-Charge Timer

Delay II

tx2

0.16s

C1=0.01

Quick Charge Timer

tx2

2hours

min. C2=0.01

NJW4120

- 14 -

Ver.2005-03-09

FEATURE DESCRIPTION (CONTINUED)

In each charge mode if time-over occurs charging is prohibited and LED-R blinks. Turning the power off to release UVLO,
battery connection detection, or CHG-SW switching will enable the charge sequence to restart.

NJW4120 incorporates a test mode that shortens the timer block function's test time by 1/150,000.
To operate in test mode set the TH pin voltage to a value no greater than that of the TL pin. In test mode, regardless of the
external timing capacitors C1, C2, the internal timer clock frequency will operate in a range of approximately 200kHz to
300kHz. The following shows calculation values when the oscillating frequency is 250kHz (4

s cycle).

Table 4. Timer Times in Test Mode.

When the TDET pin voltage is approximately 1.2V or greater, the pre-charge / quick charge timers operate normally.
If you want to further reduce the test time, setting TDET pin voltage makes it possible to run each of the timer counters
divided in half. When the TDET pin is approximately 0.3V or less, the first half of the counter is bypassed. When the voltage
is approximately greater than 0.4V and less than 1.1V, the second half of the counter is bypassed.

Table 5. Reduced Test Time Mode

Block Name

Parameter

Calculation

Formula

Example

(t = Appx. 4

2mA Charge Timer

tx2

Appx.

4ms

Pre-Charge Timer

tx2

Appx.

0.5s

LED R Blinking Cycle

tx2

Appx.

0.5ms

Delay I

tx2

Appx.

0.13ms

Pre-Charge Timer

Delay II

tx2

Appx. 64

Quick Charge Timer

tx2

Appx.

4.2s

Parameter

Calculation

Formula

Example (t =Appx. 4

Pre-Charge Timer

tx2

, tx2

Appx.

1ms,

Appx.

1ms

Quick Charge Timer

tx2

, tx2

Appx.

2ms,

Appx.

4ms

NJW4120

- 15 -

Ver.2005-03-09

FEATURE DESCRIPTION (CONTINUED)

7. Reference Voltage Block (VREF pin)

This block generates 1.24V and 4.2V reference voltages. The VREF pin outputs 1.24V. In addition to the IC internal
reference voltage, this is also used as a reference voltage for charge current setting and temperature detection setting.

8. Power Block,

Under Voltage Lockout

Circuit (UVLO) Block (V

pin, GND pin)

An integrated

Under Voltage Lockout

circuit prevents IC malfunction when power is turned on or off. This circuit

incorporates a 200mV hysteresis width to prevent chattering.
As required, insert a bypass capacitor near the IC's V

pin when there is power line noise or when wires are long.

9. LED Block (LED-R pin, LED-G pin)

The 2 LEDs can indicate charge status. (Figure 5)
The LED drive circuit is an open collector output configuration.
Therefore, it is easy to set a constant LED drive current with resistance values.
The expression for setting the current that flows through the LEDs is shown below.

LED-G

(Vcc - V

F-LED

- V

OL-G

) / R

LED

LED-R

(Vcc - V

F-LED

- V

OL-R

) / R

LED

Figure 5. LED Drive Circuit

LED-G

LED-R

Input

F-LED

LED

NJW4120

- 16 -

Ver.2005-03-09

FLOW CHART

Start

Pre-Charge

Timer Start

YES

Check

Adapter Voltage

>2.4V

Check

Battery Temp.

TDET

YES

Check

Battery Voltage

BAT

YES

Check

Voltage

BAT

Q-CHG

Quick Charge

Timer Start

Quick Charge Start

LED-G: OFF

LED-R: ON
TX-SW:ON

YES

Time Out

YES

Battery

Battery Voltage

BAT

Q-CHG

Time Out

Check

Full Charge

BAT

F-CHG

YES

Charge Complete

LED-G: ON

LED-R: OFF
TX-SW:OFF

Check

Battery Voltage

BAT

R-CHG

YES

Check

Battery Connection

CHG-SW Pin=GND

YES

Abnormal Charging

Prohibited

LED-G: OFF
LED-R: OFF

TX-SW:OFF

LED-G: OFF

LED-R: ON

2mA Charge: ON

Abnormal Charging

Prohibited

LED-G: OFF

LED-R: ON/OFF

TX-SW:OFF

Pre-Charge Start

2mACharge: OFF

TX-SW:ON

YES

Check

Battery Voltage

BAT

YES

Time Out

Check

Battery Connection

TDET

<1.15V

YES

Adaptor voltage, Battery connection,
Battery Temp. and Battery voltage are
monitored during charging.

When charging is prohibited, one of the
following action resumes the charging;
Unplug and plug power supply
Remove and set batteries
Charge-SW ON/OFF

NJW4120

- 17 -

Ver.2005-03-09

TIMING CHART

CHG-SW

LED-R

LED-G

OFF

TX-SW

OFF ON

OFF

Battery Voltage

Charge Current

Pre-

Charge

Quick

Charge

Constant

Voltage
Charge

Full

Charge

Re-

Charge

Pre-Charge Current
Full Charge Current

Quick Charge
Detecting Voltage

Quick Charge Current

Charge Control Voltage
Re-Charge Detecting Voltage

Adaptor Voltage

Charge Control Mode
Adaptor Output Mode

The timing chart at the time of protection circuit operation

In addition to a charge timing chart, a protection circuit with a built-in IC operates according to the state and
circumference environment of a battery.
The timing chart when various protection circuits operate is as follows.

Pre-charge

time

out Quick charge time out

Battery Voltage

Charge Current

CHG-SW

LED-R

LED-G

Quick charge detecting voltage

OFF

Adaptor Voltage

TX-SW

OFF

Pre-charge

! 22min* "

OFF

ON/OFF 1.28s*

Battery Voltage

Charge Current

CHG-SW

LED-R

LED-G

Charge Voltage

OFF

Adaptor Voltage

TX-SW

OFF

Quick charge

! 3h* "

OFF

ON/OFF

Full charge
detection

60mA*

C1=0.01

F C2=0.01

NJW4120

- 18 -

Ver.2005-03-09

The timing chart at the time of protection circuit operation (Continued)

Over voltage battery (Return)

Over voltage battery(Abnormalities)

Battery voltage

Charge Current

CHG-SW

LED-R

LED-G

Low voltage
Detecting voltage

OFF

Adaptor voltage

TX-SW

OFF

Pre-charge

2mA

Battery voltage

Charge Current

CHG-SW

LED-R

LED-G

OFF

Adaptor voltage

TX-SW

OFF

Charge
STOP

2mA

ON/OFF 1.28s*

Charge voltage

2mAcharge

! 10s* "

C1=0.01

2mAcharge

! 10s* "

C1=0.01

Low voltage
Detecting voltage

Over charge battery

Abnormalities in temperature

Battery Voltage

Charge Current

CHG-SW

LED-R

LED-G

OFF

Adaptor Voltage

TX-SW

OFF

Charge STOP

Battery Voltage

Charge Current

CHG-SW

LED-R

LED-G

OFF

Adaptor Voltage

TX-SW

OFF

Charge STOP

Temperature
Detecting

Over charge detecting

OFF

ON/OFF 1.28s*

C1=0.01

NJW4120

- 19 -

Ver.2005-03-09

OPERATION MATRIX

Parameter

Adaptor

Mode

Quick

Charge

Pre-

Charge

2mA

Charge

Full

Charge

Temperature

Error

Over

Voltage

Error

Time OUT

LED-G OFF OFF OFF OFF ON

OFF OFF OFF

LED-R OFF

ON ON OFF OFF

BLINKING BLINKING

SW-Tr. OFF ON ON OFF OFF OFF OFF OFF

Control Mode

Adaptor

Charge

Adaptor

Charge Current

Q-CHG

P-CHG

2mA

Return Charge

Re-Charge

Auto

Latch

Timer Stop

Operate

Stop Stop Stop -

Temperature

Detecting

Disregard Operate Operate

Operate

Operate Operate

Over Voltage

Detecting

Disregard Operate Operate

Operate

CHG-SW Stay

Operate

Re-start

Battery Setting

Stay

Operate Operate

Operate

Re-start

Full Charge

Detecting

Disregard Operate Operate Disregard

Disregard Disregard

Disregard

Disregard: Detection function is not reflected in control although it is operating.

LED ON/OFF PATTERN

*Available upon request.

NJW4120

NJW4125*

NJW4126*

NJW4127*

Parameter

LED-R

LED-G

LED-R

LED-G

LED-R

LED-G

LED-R

LED-G

Adaptor Voltage

OFF OFF OFF OFF

OFF

Charging

OFF

BLINKING

Full Charging

OFF

Temperature Error

OFF OFF

BLINKING

OFF OFF OFF

BLINKING

OFF

Over Voltage Detecting

BLINKING

OFF

BLINKING

OFF

BLINKING

OFF

BLINKING

OFF

Time Out

BLINKING

OFF

BLINKING

OFF

BLINKING

OFF

BLINKING

OFF

Ð­Ð»ÐµÐºÑ‚Ñ€Ð¾Ð½Ð½Ñ‹Ð¹ ÐºÐ¾Ð¼Ð¿Ð¾Ð½ÐµÐ½Ñ‚: NJW4120

ÐÐ»ÐµÐºÑ‚Ñ€Ð¾Ð½Ð½Ñ‹Ð¹ ÐºÐ¾Ð¼Ð¿Ð¾Ð½ÐµÐ½Ñ‚: NJW4120