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FEATURES
APPLICATIONS
DESCRIPTION
bq20z90
SLUS662A DECEMBER 2005 REVISED JUNE 2006
SBS 1.1-COMPLIANT GAS GAUGE ENABLED WITH IMPEDANCE TRACKTM
TECHNOLOGY FOR USE WITH THE bq29330
Optional Pulse Charging Feature for
Improved Charge Times
Patented Impedance TrackTM Technology
Accurately Measures Available Charge in
Drives 3-, 4- or 5-Segment LED Display for
Li-Ion and Li-Polymer Batteries
Remaining Capacity Indication
Better than 1% Error Over Lifetime of the
Supports SHA-1 Authentication
Battery
Lifetime Data Logging
Instant Accuracy No Learning Cycle
30-Pin TSSOP (DBT)
Required
Automatically adjusts for battery aging,
battery self discharge and temperature
Notebook PCs
inefficiencies
Medical and Test Equipment
Supports the Smart Battery Specification
Portable Instrumentation
SBS V1.1
Works With the TI bq29330 Analog Front-End
(AFE) Protection IC to Provide Complete Pack
The
bq20z90
SBS-compliant
gas
gauge
IC,
Electronics Solution
incorporating
patented
Impedance
TrackTM
Full Array of Programmable Voltage, Current,
technology, is designed for battery-pack or in-system
installation. The bq20z90 measures and maintains
and Temperature Protection Features
an accurate record of available charge in Li-ion or
Integrated Time Base Removes Need for
Li-polymer
batteries
using
its
integrated
External Crystal with Optional Crystal Input
high-performance analog peripherals. The bq20z90
Electronics for 7.2-V, 10.8-V or 14.4-V Battery
monitors
capacity
change,
battery
impedance,
Packs With 50% Fewer External Components
open-circuit voltage, and other critical parameters of
the battery pack, and reports the information to the
Based on a Powerful Low-Power RISC CPU
system host controller over a serial-communication
Core With High-Performance Peripherals
bus. It is designed to work with the bq29330 analog
Integrated Field Programmable FLASH
front-end
(AFE)
protection
IC
to
maximize
Memory Eliminates the Need for External
functionality and safety, and minimize component
Configuration Memory
count and cost in smart battery circuits.
Measures Charge Flow Using a
The
Impedance
Track
technology
continuously
High-Resolution, 16-Bit Integrating
analyzes the battery impedance, resulting in superior
Delta-Sigma Converter
gas-gauging
accuracy.
This
enables
remaining
capacity to be calculated with discharge rate,
Better Than 0.65 nVh of Resolution
temperature, and cell aging all accounted for during
Self-Calibrating
each stage of every cycle.
Uses 16-Bit Delta-Sigma Converter for
Accurate Voltage and Temperature
AVAILABLE OPTIONS
Measurements
PACKAGE
Extensive Data Reporting Options For
T
A
30-PIN TSSOP (DBT)
30-PIN TSSOP (DBT)
Improved System Interaction
Tube
Tape & Reel
40
C to
bq20z90DBT
(1)
bq20z90DBTR
(2)
85
C
(1)
A single tube quantity is 50 units.
(2)
A single reel quantity is 2000 units
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
IMPEDANCE TRACK is a trademark of Texas Instruments.
PRODUCTION DATA information is current as of publication date.
Copyright 20052006, Texas Instruments Incorporated
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
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SYSTEM PARTITIONING DIAGRAM
LDO +
Reset
I
2
C
SMBus
HDQ
Pack +
Pack -
Discharge / Charge /
Pre-Charge FETs
2-Tier Over Current
Protection
2k Bytes of
Data Flash
Fuse
Watchdog &
Protection Timing
C
e
l
l
B
a
l
a
n
c
i
n
g
D
r
i
v
e
System Interface
System Interface
32.768kHz
16 Dig GPIO & Peripherals
8 Dig GPIO or Analog GPI
2.5V / 3.3V (LED)
Nch FET Drive
(Charge Pumps)
RAM Configuration, Status
and Control Registers
24k x 22 Program
Flash
2k Bytes
of RAM
6k x 22
Mask ROM
C
e
l
l
,
B
a
t
a
n
d
P
a
c
k
V
o
l
t
a
g
e
T
r
a
n
s
l
a
t
i
o
n
Precharge
Control
H
o
s
t
I
n
t
e
r
f
a
c
e
&
D
a
t
a
M
a
n
a
g
e
m
e
n
t
TOUT and LEDOUT
Power Support
Reset
Analog Output Drive
32kHz Oscillator and 8MHz System Clock
T1
Standard Delta-Sigma A to D Converter
Integrating Delta-Sigma A to D Converter
1
2
7
6
5
4
3
30
29
28
27
26
25
24
NC
XALERT
SDATA
SCLK
CLKOUT
TS1
VCELL-
VCELL+
NC
RBI
VCC
VSS
MRST
TS2
PRES
SRN
PFIN
SAFE
SMBD
NC
LED4
LED5
*VSS
SRP
8
9
10
11
12
23
22
21
20
19
13
14
15
18
17
16
SMBC
DISP
NC
LED3
LED2
LED1
NC - No internal connection
bq20z90
SLUS662A DECEMBER 2005 REVISED JUNE 2006
TSSOP (DBT)
(TOP VIEW)
2
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bq20z90
SLUS662A DECEMBER 2005 REVISED JUNE 2006
TERMINAL FUNCTIONS
TERMINAL
I/O
(1)
DESCRIPTION
NO.
NAME
1
NC
Not used-- leave floating
2
XALERT
I
Input from bq29330 XALERT output.
3
SDATA
I/O
Data transfer to and from bq29330
4
SCLK
I/O
Communication clock to the bq29330
5
CLKOUT
O
32.768-kHz output for the bq29330. This pin should be directly connected to the AFE.
6
TS1
I
1
st
Thermistor voltage input connection to monitor temperature
7
TS2
I
2
nd
Thermistor voltage input connection to monitor temperature
8
PRES
I
Active low input to sense system insertion and typically requires additional ESD protection
Active low input to detect secondary protector output status and allows the bq20z90 to report the
9
PFIN
I
status of the 2
nd
level protection output
10
SAFE
O
Active high output to enforce additional level of safety protection; e.g., fuse blow.
11
SMBD
I/OD
SMBus data open-drain bidirectional pin used to transfer address and data to and from the bq20z90
12
NC
Not used-- leave floating
13
SMBC
I/OD
SMBus clock open-drain bidirectional pin used to clock the data transfer to and from the bq20z90
Display control for the LEDs. This pin is typically connected to bq29330 REG via a 100-k
resistor
14
DISP
I
and a push-button switch to VSS.
15
NC
Not used-- leave floating
16
LED1
O
LED1 display segment that drives an external LED depending on the firmware configuration
17
LED2
O
LED2 display segment that drives an external LED depending on the firmware configuration
18
LED3
O
LED3 display segment that drives an external LED depending on the firmware configuration
19
LED4
O
LED4 display segment that drives an external LED depending on the firmware configuration
20
LED5
O
LED5 display segment that drives an external LED depending on the firmware configuration
21
VSS
Connected I/O pin to VSS
Connections to the top of a small-value sense resistor to monitor the battery charge- and
22
SRP
IA
discharge-current flow
Connections to the bottom of a small-value sense resistor to monitor the battery charge- and
23
SRN
IA
discharge-current flow
Master reset input that forces the device into reset when held low. Must be held high for normal
24
MRST
I
operation
25
VSS
P
Negative Supply Voltage
26
VCC
P
Positive Supply Voltage
Backup power to the bq20z90 data registers during periods of low operating voltage. RBI accepts a
27
RBI
P
storage capacitor or a battery input.
28
NC
Not used-- leave floating
29
VCELL+
I
Input from bq29330 used to read a scaled value of individual cell voltages
30
VCELL-
I
Input from bq29330 used to read a scaled value of individual cell voltages
(1)
I = Input, IA = Analog input, I/O = Input/output, I/OD = Input/Open-drain output, O = Output, OA = Analog output, P = Power
3
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ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
bq20z90
SLUS662A DECEMBER 2005 REVISED JUNE 2006
over operating free-air temperature range (unless otherwise noted)
(1)
RANGE
V
CC
relative to V
SS
Supply voltage range
0.3 V to 2.75 V
V
(IOD)
relative to V
SS
Open-drain I/O pins
0.3 V to 6 V
V
I
relative to V
SS
Input voltage range to all other pins
0.3 V to V
CC
+ 0.3 V
T
A
Operating free-air temperature range
40
C to 85
C
T
stg
Storage temperature range
65
C to 150
C
(1)
Stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. These are stress ratings
only, and functional operation of the device at these or any other conditions beyond those indicated under recommended operating
conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
V
CC
= 2.4 V to 2.6 V, T
A
= 40
C to 85
C (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
V
CC
Supply voltage
2.4
2.5
2.6
V
No flash programming
400
(1)
I
CC
Operating mode current
A
bq20z90 + bq29330
475
Sleep mode
8
(1)
I
(SLP)
Low-power storage mode current
A
bq20z90 + bq29330
51
Output voltage low SMBC, SMBD, SDATA, SCLK, SAFE
I
OL
= 0.5 mA
0.4
V
V
OL
LED1 LED5
I
OL
= 10 mA
0.4
V
V
OH
Output high voltage, SMBC, SMBD, SDATA, SCLK, SAFE
I
OH
= 1 mA
V
CC
0.5
V
V
IL
Input voltage low SMBC, SMBD, SDATA, SCLK, XALERT,
0.3
0.8
V
PRES, PFIN
DISP
0.3
0.8
V
V
IH
Input voltage high SMBC, SMBD, SDATA, SCLK, XALERT,
2
6
V
PRES, PFIN
DISP
2
V
CC
+ 0.3
V
C
IN
Input capacitance
5
pF
V
(AI1)
Input voltage range VCELL+, VCELL-,TS1, TS2
- 0.2
0.8XV
CC
V
V
(AI2)
Input voltage range SR1, SR2
0.20
0.20
Z
(AI2)
Input impedance VCELL+, VCELL-, TS1, TS2
0 V1 V
8
M
Z
(AI1)
Input impedance SR1, SR2
0 V1 V
2.5
M
(1)
This value does not include the bq29330
4
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POWER-ON RESET
1.76
1.77
1.78
1.79
1.8
1.81
-40
-20
0
20
40
60
80
T - Free-Air Temperature - C
A
Power-OnResetNegative-GoingV
oltage-V
POWER ON RESET BEHAVIOR
FREE-AIR TEMPERATURE
VS
INTEGRATING ADC (Coulomb Counter) CHARACTERISTICS
OSCILLATOR
bq20z90
SLUS662A DECEMBER 2005 REVISED JUNE 2006
V
CC
= 2.4V to 2.6 V, T
A
= 40
C to 85
C (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
V
IT
Negative-going voltage input
1.7
1.8
1.9
V
V
HYS
Power-on reset hysteresis
50
125
200
mV
V
CC
= 2.4V to 2.6 V, T
A
= 40
C to 85
C (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
V
(SR)
Input voltage range, V
(SRN)
and V
(SRP)
V
(SR)
= V(SRN) V(SRP)
0.2
0.2
V
V
(SROS)
Input offset
10
V
INL
Integral nonlinearity error
0.007%
0.034%
V
CC
= 2.4 V to 2.6 V, T
A
= 40
C to 85
C (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
HIGH FREQUENCY OSCILLATOR
f
(OSC)
Operating Frequency
4.194
MHz
-3%
0.25%
3%
f
(EIO)
Frequency Error
(1) (2)
T
A
= 20
C to 70
C
-2%
0.25%
2%
t
(SXO)
Start-up Time
(3)
2.5
5
ms
LOW FREQUENCY OSCILLATOR
f
(LOSC)
Operating Frequency
32.768
KHz
-2.5%
0.25%
2.5%
f
(LEIO)
Frequency Error
(2) (4)
T
A
= 20
C to 70
C
-1.5%
0.25%
1.5%
(1)
The frequency error is measured from 4.194 MHz.
(2)
The frequency drift is included and measured from the trimmed frequency at V
CC
= 2.5 V, T
A
= 25
C.
(3)
The start-up time is defined as the time it takes for the oscillator output frequency to be within 1% of the specified frequency.
(4)
The frequency error is measured from 32.768 kHz.
5
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