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
SMALL PACKAGE PWM CONTROL
STEP-UP SWITCHING REGULATOR
S-8323/8327 Series
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
Low voltage operation: 0.9 V (I
OUT
= 1mA)
Low current consumption :
Applications
Power supplies for portable equipment such as
pagers, handy calculators, and remote controllers
During operation: 17.2µA (typ.)
(V
OUT
= 3 V, 50 kHz)
During shutdown : 0.5µA (max.)
Duty ratio:
Constant voltage power supplies for cameras,
video equipment, and communications equipment
Power supply for microcomputers
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
CONT
V
OUT
(2) S-8327 Series
V
OUT
VREF
PWM
control
circuit
+
-
PWM
control
circuit
VREF
+
-
EXT
V
SS
Soft start circuit
Soft start circuit
V
SS
(ON / OFF)
(ON / OFF)
Figure 1 Block Diagram
Seiko Instruments Inc.
1
SMALL PACKAGE PWM CONTROL STEP-UP SWITCHING REGULATOR
S-8323/8327 Series
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)
2.0
2.5
2.7
3.0
3.3
5.0
5.2
Output voltage
(V)
2.0
2.5
2.7
2.8
3.0
3.3
3.6
5.0
5.4
S-8323AXXMC
Series
—
S-8323A25MC-ELF-T2
S-8323A27MC-ELH-T2
S-8323A30MC-ELK-T2
S-8323A33MC-ELN-T2
S-8323A50MC-EME-T2
S-8323A52MC-EMG-T2
S-8327BXXMC
Series
—
S-8327B25MC-ERF-T2
S-8327B27MC-ERH-T2
S-8327B28MC-ERI-T2
S-8327B30MC-ERK-T2
S-8327B33MC-ERN-T2
S-8327B36MC-ERQ-T2
S-8327B50MC-ESE-T2
S-8327B54MC-ESI-T2
S-8323AXXMA
Series
—
S-8323A25MA-ELF-T2
S-8323A27MA-ELH-T2
S-8323A30MA-ELK-T2
S-8323A33MA-ELN-T2
S-8323A50MA-EME-T2
—
S-8327BXXMA
Series
—
S-8327B25MA-ERF-T2
S-8327B27MA-ERH-T2
—
S-8327B30MA-ERK-T2
S-8327B33MA-ERN-T2
—
S-8327B50MA-ESE-T2
—
S-8323AXXUA
Series
—
S-8323A25UA-ELF-T2
S-8323A27UA-ELH-T2
S-8323A30UA-ELK-T2
S-8323A33UA-ELN-T2
S-8323A50UA-EME-T2
—
S-8327BXXUA
Series
—
S-8327B25UA-ERF-T2
S-8327B27UA-ERH-T2
—
S-8327B30UA-ERK-T2
S-8327B33UA-ERN-T2
—
S-8327B50UA-ESE-T2
—
S-8323CXXMA
Series
—
S-8323C25MA-ENF-T2
S-8323C27MA-ENH-T2
S-8323C30MA-ENK-T2
—
—
—
S-8327EXXMC
Series
S-8327E20MC-EVA-T2
—
—
—
—
—
—
S-8327E50MC-EKE-T2
—
S-8323DXXMC
Series
S-8323D20MC-EZA-T2
—
—
S-8323D30MC-EZK-T2
—
S-8323D50MC-E3E-T2
—
Consult our sales person for products with an output voltage other than specified above.
3. Function List
Built In power with external Switching shutdown V
DD
/V
OUT
transistor
power
frequency function separate Package
Application
Reference
transistor
(kHz)
type
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
—
For variable output voltage by
S-8323DXXMC
Yes
—
50
—
Yes
SOT-23-5
step-up DC/DC converter and
Page 16
step-down, inverted output DC/DC
converter with an external resistor
S-8323CXXMA
Yes
—
30
—
—
SOT-23-3 For pagers
—
For large load current with
Pages 15 and 16
S-8327BXXMC
—
Yes
100
Yes
—
SOT-23-5 shutdown function
For large load current without
Pages 15 and 16
S-8327BXXMA
—
Yes
100
—
—
SOT-23-3 shutdown function
For large load current without
Pages 15 and 16
S-8327BXXUA
—
Yes
100
—
—
SOT-89-3 shutdown function
For variable output voltage by
S-8327EXXMC
—
Yes
100
—
Yes
SOT-23-5 step-up DC/DC converter with an
Page 16
external resistor
Product Name
2
Seiko Instruments Inc.
SMALL PACKAGE PWM CONTROL STEP-UP SWITCHING REGULATOR
S-8323/8327 Series
Pin Assignment
5
SOT-23-5
Top view
4
SOT-23-3
Top view
1
2
3
2
SOT-89-3
Top view
1
3
Figure 2
1
2
3
S-8323AXXMC, S-8327BXXMC
S-8323DXXMC, S-8327EXXMC
SOT-23-5
Pin No.
1
Functions
Shutdown pin
“H”:
normal operation
ON / OFF
(stepping up operation)
“L”:
stop stepping up
(whole circuit stop)
V
OUT
Output voltage pin and power
supply pin
—
N.C. (Non Connection)
V
SS
GND pin
CONT External inductor connection
pin (for S-8323 Series)
External transistor connection
EXT
pin (for S-8327 Series)
Pin name
SOT-23-5
Pin No.
1
2
3
4
5
Pin name
V
OUT
V
DD
—
V
SS
CONT
EXT
Functions
Output voltage pin
Power supply pin
N.C. (Non Connection)
GND pin
External inductor connection
pin (for S-8323 Series)
External transistor connection
pin (for S-8327 Series)
2
3
4
5
S-8323AXXMA, S-8323AXXUA, S-8323CXXMA
S-8327BXXMA, S-8327BXXUA
SOT-23-3, SOT-89-3
Pin No.
1
2
Pin name
Functions
V
SS
GND pin
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)
3
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.
( Unless otherwise specified: Ta=25°C)
Parameter
VOUT pin voltage
ON/OFF pin voltage
CONT pin voltage
CONT pin current
EXT pin voltage
EXT pin current
Power dissipation
Operating temperature
Storage temperature
PD
Symbol
V
OUT
ON/OFF
V
CONT
I
CONT
V
EXT
I
EXT
SOT-89-3
SOT-23-5, SOT-23-3
T
OPR
T
STG
Ratings
11
V
ss
- 0.3 to 11
11
300
V
ss
- 0.3 to V
OUT
+0.3
±50
500
150
-40 to +85
-40 to +125
°C
°C
Unit
V
V
V
mA
V
mA
mW
Seiko Instruments Inc.
3
SMALL PACKAGE PWM CONTROL STEP-UP SWITCHING REGULATOR
S-8323/8327 Series
Electrical Characteristics
1-1.S-8323AXXMC
(Unless otherwise specified: Ta=25°C)
Min.
Typ.
Max.
Unit
Test circuit
S-8323A52MC
S-8323A50MC
S-8323A33MC
S-8323A30MC
S-8323A27MC
S-8323A25MC
I
OUT
=1mA
No external parts, voltage applied to V
OUT
CONT pulled up to 5 V by 10kΩ
I
OUT
=1mA, Measured by decreasing V
IN
voltage
graduelly
S-8323A52MC
S-8323A50MC
V
OUT
=output voltage×0.95
S-8323A33MC
S-8323A30MC
S-8323A27MC
S-8323A25MC
S-8323A52MC
S-8323A50MC
V
OUT
=output voltage+0.5
S-8323A33MC
S-8323A30MC
S-8323A27MC
S-8323A25MC
shutdown pin=0V
S-8323A52MC
S-8323A50MC
S-8323A33MC
S-8323A30MC
S-8323A27MC
S-8323A25MC
4.075
4.880
3.221
2.928
2.635
2.440
—
—
—
0.7
—
—
—
—
—
—
—
—
—
—
—
—
—
114
114
78
78
61
61
—
—
—
—
—
—
—
—
—
42.5
75
0.75
—
—
3.0
—
—
—
—
—
—
5.200
5.000
3.300
3.000
2.700
2.500
—
—
—
—
31.6
30.2
19.1
17.2
15.5
14.3
3.5
3.5
3.3
3.2
3.2
3.2
—
182
182
125
125
98
98
—
30
30
±0.26
±0.25
±0.17
±0.15
±0.14
±0.13
50
83
—
—
—
6.0
87
87
83
83
79
79
5.325
5.120
3.379
3.072
2.765
2.560
9
0.9
0.8
—
52.6
50.3
31.8
28.7
25.9
23.9
6.9
6.9
6.5
6.4
6.4
6.3
0.5
—
—
—
—
—
—
1.0
60
60
—
—
—
—
—
—
57.5
90
—
0.3
0.2
12.0
—
—
—
—
—
—
ms
—
V
Parameter
Symbol
Conditions
Output voltage
V
OUT
V
1
Input voltage
Operation start voltage
Oscillation start voltage
Operation holding voltage
V
IN
V
ST1
V
ST2
V
HLD
2
1
Current consumption 1
I
SS1
µA
2
Current consumption 2
I
SS2
Current consumption during
shutdown
I
SSS
Switching current
I
SW
VCONT=0.4V
mA
—
Switchin transistor leak
current
Line regulation
Load regulation
Output voltage
temperature
coefficient
I
SWQ
∆V
OUT1
∆V
OUT2
∆V
OUT
/∆Ta
V
OUT
= VCONT=10V
V
IN
=output voltage×0.4 to
×0.6
I
OUT
=10µA to I
OUT
(below)
×1.25
S-8323A52MC
S-8323A50MC
S-8323A33MC
S-8323A30MC
S-8323A27MC
S-8323A25MC
µA
mV
—
1
mV/°C
Ta=-40°C to +85°C
Oscillation frequency
Max. duty ratio
fosc
MaxDuty
VSH
Shutdown pin
Input voltage
(ON/OFF type)
VSL1
VSL2
V
OUT
=output voltage×0.95
Measured waveform at CONT pin
V
OUT
=output voltage×0.95
Measured waveform at CONT pin
V
OUT
=output voltage×0.95
Measured the oscillation at CONT pin
V
OUT
=output voltage×0.95
When
V
OUT
≥1.5V
Judged the stop of oscillation When
at CONT pin
V
OUT
<1.5V
S-8323A52MC
S-8323A50MC
S-8323A33MC
S-8323A30MC
S-8323A27MC
S-8323A25MC
kHz
%
2
Soft start time
T
SS
Efficiency
EFFI
%
1
External parts used:
- Coil:
CD54 (100µH) of Sumida Electric Co., Ltd.
- Diode:
MA720 (Schottky type) of Matsushita Electronic Components Co., Ltd.
- Capacitor: F93 (16V, 22µF, tantalum type) of Nichicon Corporation)
Applied V
IN
=output voltage×0.6, applied, I
OUT
=output voltage/250Ω
The shutdown pin is connected to V
OUT
pin.
Note 1: The output voltage specified above is the typical value.
4
Seiko Instruments Inc.
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