Contents
Features .............................................................. 1
Applications ......................................................... 1
Block Diagram ..................................................... 1
Selection Guide ................................................... 2
Pin Assignment ................................................... 3
Absolute Maximum Ratings ................................. 3
Electrical Characteristics ..................................... 4
Test Circuits ........................................................ 9
Operation............................................................. 10
External parts selection for DC-DC converter ...... 13
Standard Circuits ................................................. 17
Precautions ......................................................... 19
Application Circuits .............................................. 20
Dimensions.......................................................... 25
Markings.............................................................. 25
Taping ................................................................ 26
Temperature Characteristics .............................. 29
Voltage Characteristics ....................................... 31
Ripple Characteristics ......................................... 32
Transient Responses .......................................... 33
Operation Start Voltage and Operation Holding
Voltage Characteristics for Output Current ......... 35
Input Voltage Characteristics for Input Current ... 35
Reference Data .................................................. 36
Frequently Asked Questions .............................. 45
Seiko Instruments Inc.
1
S-8323/8327 Series
SMALL PACKAGE PWM CONTROL
STEP-UP SWITCHING REGULATOR
The S-8323/8327 Series is a CMOS PWM-control step-up switching
regulator which mainly consists of a reference voltage source, an
oscillation circuit, a power MOS FET (for S-8323 Series) , and an error
amplifier. The new PWM control circuit automatically changes the duty
ratio from 0% to 83% according to the current load, offering products of
a wide range, high efficiency. A step-up switching regulator is
constructed by externally connecting only a coil, a capacitor and a diode
to the S-8323 Series. This feature, along with its small package and low
current consumption, makes the S-8323 Series ideal for the power
supply of portable equipment. For applications requiring a high output
current, products used with an external transistor (S-8327 Series) are
also available.
Features
Applications
Low voltage operation: 0.9 V (I
OUT
= 1mA)
Power supplies for portable equipment such as
Low current consumption :
pagers, handy calculators, and remote controllers
During operation: 17.2
A (typ.)
Constant voltage power supplies for cameras,
(V
OUT
= 3 V, 50 kHz)
video equipment, and communications equipment
During shutdown : 0.5
A (max.)
Power supply for microcomputers
Duty ratio:
Built-in PWM control circuit
External parts: coil, diode, and capacitor only
(a transistor is needed for the S-8327 Series.)
Output voltage: accuracy of 2.4%
Soft start function: 6 msec (typ.)
Shutdown function
External transistor type is available (S-8327 Series)
SOT-23-5 small plastic package
SOT-23-3 small plastic package
SOT-89-3 miniature power molded plastic package
Step-down and voltage-inverting type are available.
Block Diagram
(1)
S-8323 Series
(2)
S-8327 Series
Figure 1 Block Diagram
(ON / OFF)
EXT
(ON / OFF)
V
SS
V
OUT
CONT
PWM
control
circuit
-
+
VREF
V
SS
V
OUT
PWM
control
circuit
-
+
VREF
Soft start circuit
Soft start circuit
SMALL PACKAGE PWM CONTROL STEP-UP SWITCHING REGULATOR
S-8323/8327 Series
2
Seiko Instruments Inc.
Selection Guide
1. Product Name
S
-
832 X X XX XX -
XXX - T2
Tape Specification
Product name (abbreviation)
Package name (abbreviation)
MA: SOT-23-3 (without shutdown function)
MC: SOT-23-5 (with shutdown function, V
DD
/Vout separate product)
UA: SOT-89-3 (without shutdown function)
Output voltage x 10
Product category
A: Normal product, fosc=50 kHz (S-8323 only)
B: Normal product, fosc=100 kHz (S-8327 only)
C: For pagers, fosc=30 kHz (S-8323 only)
D : V
DD
/Vout separate product, fosc=50 kHz (S-8323 only)
E : V
DD
/Vout separate product, fosc=100 kHz (S-8327 only)
Power transistor
3: Built-in switch.
7: External transistor.
2. Product list
Output voltage
(V)
S-8323AXXMC
Series
S-8323AXXMA
Series
S-8323AXXUA
Series
S-8323CXXMA
Series
S-8323DXXMC
Series
2.0
--
--
--
--
S-8323D20MC-EZA-T2
2.5
S-8323A25MC-ELF-T2
S-8323A25MA-ELF-T2
S-8323A25UA-ELF-T2
S-8323C25MA-ENF-T2
--
2.7
S-8323A27MC-ELH-T2
S-8323A27MA-ELH-T2
S-8323A27UA-ELH-T2
S-8323C27MA-ENH-T2
--
3.0
S-8323A30MC-ELK-T2
S-8323A30MA-ELK-T2
S-8323A30UA-ELK-T2
S-8323C30MA-ENK-T2
S-8323D30MC-EZK-T2
3.3
S-8323A33MC-ELN-T2
S-8323A33MA-ELN-T2
S-8323A33UA-ELN-T2
--
--
5.0
S-8323A50MC-EME-T2
S-8323A50MA-EME-T2
S-8323A50UA-EME-T2
--
S-8323D50MC-E3E-T2
5.2
S-8323A52MC-EMG-T2
--
--
--
--
Output voltage
(V)
S-8327BXXMC
Series
S-8327BXXMA
Series
S-8327BXXUA
Series
S-8327EXXMC
Series
2.0
--
--
--
S-8327E20MC-EVA-T2
2.5
S-8327B25MC-ERF-T2
S-8327B25MA-ERF-T2
S-8327B25UA-ERF-T2
--
2.7
S-8327B27MC-ERH-T2
S-8327B27MA-ERH-T2
S-8327B27UA-ERH-T2
--
2.8
S-8327B28MC-ERI-T2
--
--
--
3.0
S-8327B30MC-ERK-T2
S-8327B30MA-ERK-T2
S-8327B30UA-ERK-T2
--
3.3
S-8327B33MC-ERN-T2
S-8327B33MA-ERN-T2
S-8327B33UA-ERN-T2
--
3.6
S-8327B36MC-ERQ-T2
--
--
--
5.0
S-8327B50MC-ESE-T2
S-8327B50MA-ESE-T2
S-8327B50UA-ESE-T2
S-8327E50MC-EKE-T2
5.4
S-8327B54MC-ESI-T2
--
--
--
Consult our sales person for products with an output voltage other than specified above.
3. Function List
Product Name
Built In power
transistor
with external
power
transistor
Switching
frequency
(kHz)
shutdown
function
V
DD
/V
OUT
separate
type
Package
Application
Reference
page
S-8323AXXMC
Yes
--
50
Yes
--
SOT-23-5 With shutdown function
--
S-8323AXXMA
Yes
--
50
--
--
SOT-23-3 Without shutdown function
--
S-8323AXXUA
Yes
--
50
--
--
SOT-89-3 Without shutdown function
--
S-8323DXXMC
Yes
--
50
--
Yes
SOT-23-5 For variable output voltage by
step-up DC/DC converter and
step-down, inverted output DC/DC
converter with an external resistor
Page 16
S-8323CXXMA
Yes
--
30
--
--
SOT-23-3 For pagers
--
S-8327BXXMC
--
Yes
100
Yes
--
SOT-23-5
For large load current with
shutdown function
Pages 15 and 16
S-8327BXXMA
--
Yes
100
--
--
SOT-23-3
For large load current without
shutdown function
Pages 15 and 16
S-8327BXXUA
--
Yes
100
--
--
SOT-89-3
For large load current without
shutdown function
Pages 15 and 16
S-8327EXXMC
--
Yes
100
--
Yes
SOT-23-5
For variable output voltage by
step-up DC/DC converter with an
external resistor
Page 16
SMALL PACKAGE PWM CONTROL STEP-UP SWITCHING REGULATOR
S-8323/8327 Series
Seiko Instruments Inc.
3
Pin Assignment
Figure 2
Absolute Maximum Ratings
Note:
A protect circuit for static electricity is built into this IC chip.
However, prevent a charge of static electricity which exceeds the capacity of the protect circuit.
Pin No.
Pin name
Functions
1
ON / OFF
Shutdown pin
"H":
normal operation
(stepping up operation)
"L":
stop stepping up
(whole circuit stop)
2
V
OUT
Output voltage pin and power
supply pin
3
--
N.C. (Non Connection)
4
V
SS
GND pin
CONT
External inductor connection
pin (for S-8323 Series)
EXT
External transistor connection
pin (for S-8327 Series)
Pin No.
Pin name
Functions
1
V
OUT
Output voltage pin
2
V
DD
Power supply pin
3
--
N.C. (Non Connection)
4
V
SS
GND pin
CONT
External inductor connection
pin (for S-8323 Series)
EXT
External transistor connection
pin (for S-8327 Series)
Pin No.
Pin name
Functions
1
V
SS
GND pin
2
V
OUT
Output voltage pin and power
supply pin
CONT
External inductor connection
pin (for S-8323 Series)
EXT
External transistor connection
pin (for S-8327 Series)
Parameter
Symbol
Ratings
Unit
VOUT pin voltage
V
OUT
11
V
ON/OFF pin voltage
ON/OFF
V
ss
- 0.3 to 11
V
CONT pin voltage
V
CONT
11
V
CONT pin current
I
CONT
300
mA
EXT pin voltage
V
EXT
V
ss
- 0.3 to V
OUT
+0.3
V
EXT pin current
I
EXT
50
mA
Power dissipation
PD
SOT-89-3
500
mW
SOT-23-5, SOT-23-3
150
Operating temperature
T
OPR
-40 to +85
C
Storage temperature
T
STG
-40 to +125
C
2
3
1
SOT-23-3
Top view
5
4
3
2
1
SOT-23-5
Top view
3
2
1
SOT-89-3
Top view
5
S-8323AXXMC, S-8327BXXMC
SOT-23-5
5
S-8323DXXMC, S-8327EXXMC
SOT-23-5
S-8323AXXMA, S-8323AXXUA, S-8323CXXMA
S-8327BXXMA, S-8327BXXUA
SOT-23-3, SOT-89-3
3
( Unless otherwise specified: Ta=25
C)
SMALL PACKAGE PWM CONTROL STEP-UP SWITCHING REGULATOR
S-8323/8327 Series
4
Seiko Instruments Inc.
Electrical Characteristics
1-1.S-8323AXXMC
(Unless otherwise specified: Ta=25
C)
Parameter
Symbol
Conditions
Min.
Typ.
Max.
Unit
Test circuit
S-8323A52MC
4.075
5.200
5.325
S-8323A50MC
4.880
5.000
5.120
Output voltage
V
OUT
S-8323A33MC
3.221
3.300
3.379
S-8323A30MC
2.928
3.000
3.072
S-8323A27MC
2.635
2.700
2.765
V
1
S-8323A25MC
2.440
2.500
2.560
Input voltage
V
IN
--
--
9
Operation start voltage
V
ST1
I
OUT
=1mA
--
--
0.9
Oscillation start voltage
V
ST2
No external parts, voltage applied to V
OUT
CONT pulled up to 5 V by 10k
--
--
0.8
2
Operation holding voltage
V
HLD
I
OUT
=1mA, Measured by decreasing V
IN
voltage
graduelly
0.7
--
--
1
S-8323A52MC
--
31.6
52.6
S-8323A50MC
--
30.2
50.3
Current consumption 1
I
SS1
V
OUT
=output voltage
0.95
S-8323A33MC
--
19.1
31.8
S-8323A30MC
--
17.2
28.7
S-8323A27MC
--
15.5
25.9
S-8323A25MC
--
14.3
23.9
S-8323A52MC
--
3.5
6.9
A
2
S-8323A50MC
--
3.5
6.9
Current consumption 2
I
SS2
V
OUT
=output voltage+0.5
S-8323A33MC
--
3.3
6.5
S-8323A30MC
--
3.2
6.4
S-8323A27MC
--
3.2
6.4
S-8323A25MC
--
3.2
6.3
Current consumption during
shutdown
I
SSS
shutdown pin=0V
--
--
0.5
S-8323A52MC
114
182
--
S-8323A50MC
114
182
--
Switching current
I
SW
VCONT=0.4V
S-8323A33MC
78
125
--
mA
--
S-8323A30MC
78
125
--
S-8323A27MC
61
98
--
S-8323A25MC
61
98
--
Switchin transistor leak
current
I
SWQ
V
OUT
= VCONT=10V
--
--
1.0
A
--
Line regulation
V
OUT1
V
IN
=output voltage
0.4 to
0.6
--
30
60
mV
Load regulation
V
OUT2
I
OUT
=10
A to I
OUT
(below)
1.25
--
30
60
S-8323A52MC
--
0.26
--
Output voltage
S-8323A50MC
--
0.25
--
1
temperature
V
OUT
/
Ta
Ta=-40
C to +85
C
S-8323A33MC
--
0.17
--
mV/
C
coefficient
S-8323A30MC
--
0.15
--
S-8323A27MC
--
0.14
--
S-8323A25MC
--
0.13
--
Oscillation frequency
fosc
V
OUT
=output voltage
0.95
Measured waveform at CONT pin
42.5
50
57.5
kHz
Max. duty ratio
MaxDuty
V
OUT
=output voltage
0.95
Measured waveform at CONT pin
75
83
90
%
Shutdown pin
VSH
V
OUT
=output voltage
0.95
Measured the oscillation at CONT pin
0.75
--
--
2
Input voltage
(ON/OFF type)
VSL1
V
OUT
=output voltage
0.95
When
V
OUT
1.5V
--
--
0.3
V
VSL2
Judged the stop of oscillation
at CONT pin
When
V
OUT
<1.5V
--
--
0.2
Soft start time
T
SS
3.0
6.0
12.0
ms
--
S-8323A52MC
--
87
--
S-8323A50MC
--
87
--
Efficiency
EFFI
S-8323A33MC
--
83
--
%
1
S-8323A30MC
--
83
--
S-8323A27MC
--
79
--
S-8323A25MC
--
79
--
External parts used:
- Coil:
CD54 (100
H) of Sumida Electric Co., Ltd.
- Diode:
MA720 (Schottky type) of Matsushita Electronic Components Co., Ltd.
- Capacitor: F93 (16V, 22
F, tantalum type) of Nichicon Corporation)
Applied V
IN
=output voltage
0.6, applied, I
OUT
=output voltage/250
The shutdown pin is connected to V
OUT
pin.
Note 1: The output voltage specified above is the typical value.
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