Contents
Features .............................................................. 1
Applications ......................................................... 1
Block Diagram ..................................................... 1
Selection Guide ................................................... 2
Pin Assignment ................................................... 2
Absolute Maximum Ratings ................................. 2
Electrical Characteristics ..................................... 3
Test Circuits ........................................................ 7
Operation............................................................. 8
External Part Selection ........................................ 11
Standard Circuits ................................................. 13
Precautions ......................................................... 13
Dimensions.......................................................... 14
Markings.............................................................. 14
Taping ................................................................. 15
Characteristics (typical data) ............................... 17
Reference Data (1) .............................................. 19
Reference Data (2) .............................................. 22
Frequently Asked Questions ............................... 28
SMALL PACKAGE PFM CONTROL
STEP-UP SWITCHING REGULATOR
S-8321/8322 Series
The S-8321/8322 Series is a CMOS PFM-control step-up switching
regulator which mainly consists of a reference voltage source, an
oscillation circuit, a power MOS FET, and a comparator. The new
method PFM control circuit automatically switches the duty ratio
according to load, offering products of low ripple over a wide range, high
efficiency, high output current.
A step-up switching regulator is
constructed by externally connecting only a coil, a capacitor and a diode
to the S-8321/8322 Series. This feature, along with its small package
and low current consumption, makes the S-8321/8322 Series ideal for
the power supply of portable equipment. A built-in protection circuit
prevents damage to the IC by turning off the MOS FET when the
voltage at CONT pin exceeds the limit during ON of the built-in MOS
FET. For applications requiring a high output current, products used
with an external transistor are also available in S-8322 Series.
•
•
•
•
•
•
•
•
Features
Low voltage operation: 0.9 V min. (I
OUT
= 1 mA)
Low input current:
During operation: 6.8
µ
A (V
OUT
= 3 V, no load, typ.)
During shutdown: 0.5
µ
A (max.)
Duty ratio: auto-switching PFM control circuit type
External parts: coil, diode, and capacitor only
Output voltage: accuracy of
±
2.4%
Shutdown function
External transistor type is available (S-8322 Series)
A Series : SOT-23-5 package
B Series : SOT-23-3 package
•
•
•
Applications
Power supplies for portable equipment such
as pagers, handy calculators, and remote
controllers
Constant voltage power supplies for cameras,
video equipment, and communications
equipment
Power supply for microcomputers
Block Diagram
(1) S-8321
Series
CONT
Protection
circuit
VOUT
(2)
S-8322
Series
VOUT
VREF
+
-
VREF
+
-
PFM control
circuit
EXT
PFM control
circuit
VSS
VSS
(ON / OFF)
(ON / OFF)
Figure 1
Seiko Instruments Inc.
1
SMALL PACKAGE PFM CONTROL STEP-UP SWITCHING REGULATOR
S-8321/8322 Series
Selection Guide
1. Name of the Product
S-832 X X X MP - XXX - T2
Tape Specification
Product name (abbreviation)
Output voltage (symbol)
Series name
A : SOT-23-5 / auto-switching type
B : SOT-23-3 / auto-switching type
Power MOS FET
1 : Built in
2 : Connected externally
2. List of the Product
Products
Output voltage (V)
S-8321A Series
S-8322A Series
S-8321B Series
S-8322B Series
2.2
S-8321AOMP-DNO-T2
2.5
S-8321AJMP-DNJ-T2 S-8322AJMP-DOJ-T2 S-8321BJMP-DTJ-T2
2.7
S-8321ALMP-DNL-T2
S-8321BLMP-DTL-T2
3.0
S-8321AIMP-DNI-T2
S-8322AIMP-DOI-T2
S-8321BIMP-DTI-T2
S-8322BIMP-DUI-T2
3.3
S-8321AGMP-DNG-T2 S-8322AGMP-DOG-T2 S-8321BGMP-DTG-T2
3.5
S-8321AFMP-DNF-T2 S-8322AFMP-DOF-T2
5.0
S-8321AAMP-DNA-T2 S-8322AAMP-DOA-T2 S-8321BAMP-DTA-T2 S-8322BAMP-DUA-T2
5.5
S-8321AMMP-DNM-T2
Consult our sales person for products with an output voltage other than specified above.
Pin Assignment
(1) SOT - 23 - 5
Top view
5
4
(2) SOT - 23 - 3
Top view
2
Pin name
Functions
Shutdown pin
ON / OFF “H”: normal operation (stepping up
operation)
“L”: stop stepping up (circuit stop)
V
OUT
V
SS
Output voltage pin and IC power supply
GND
External inductor connection
Note 1
External transistor connection Note 2
1
1
2
3
4
5
2
3
1
x
CONT
EXT
ON / OFF
V
OUT
NC
V
SS
CONT / EXT
1 V
SS
2 V
OUT
3 CONT / EXT
Note 1: S-8321 Series : Open drain output
Note 2: S-8322 Series: CMOS output
Figure 2
Absolute Maximum Ratings
( Unless otherwise specified: Ta=25
°
C )
Parameter
V
OUT
pin voltage
ON/OFF pin voltage
CONT pin voltage
CONT pin current
EXT pin voltage
EXT pin current
Power dissipation
Operating temperature
Storage temperature
Symbol
V
OUT
ON/OFF
V
CONT
I
CONT
V
EXT
I
EXT
PD
T
OPR
T
STG
Ratings
11
Vss-0.3 to 11
11
300
Vss-0.3 to VOUT+0.3
±
50
Unit
V
V
V
mA
V
mA
mW
°
C
°
C
150
-40 to +85
-40 to +125
2
Seiko Instruments Inc.
SMALL PACKAGE PFM CONTROL STEP-UP SWITCHING REGULATOR
S-8321/8322 Series
Electrical Characteristics
1-1 S-8321AXMP
( Unless otherwise specified: Ta=25
°
C )
Parameter
Symbol
Conditions
S-8321AMMP
S-8321AAMP
S-8321AFMP
S-8321AGMP
S-8321AIMP
S-8321ALMP
S-8321AJMP
S-8321AOMP
I
OUT
=1mA
No external parts, voltage applied to V
OUT
,
CONT pulled up to 5 V by 10k
Ω
S-8321AMMP
S-8321AAMP
S-8321AFMP
S-8321AGMP
No load
S-8321AIMP
S-8321ALMP
S-8321AJMP
S-8321AOMP
S-8321AMMP
S-8321AAMP
S-8321AFMP
S-8321AGMP
V
OUT
=output voltage
×
0.95
S-8321AIMP
S-8321ALMP
S-8321AJMP
S-8321AOMP
S-8321AMMP
S-8321AAMP
S-8321AFMP
S-8321AGMP
V
OUT
=output voltage+0.5
S-8321AIMP
S-8321ALMP
S-8321AJMP
S-8321AOMP
Shutdown pin=0 V
S-8321AMMP
S-8321AAMP
S-8321AFMP
S-8321AGMP
V
CONT
=0.4V
S-8321AIMP
S-8321ALMP
S-8321AJMP
S-8321AOMP
V
OUT
=V
CONT
=0.9V
V
IN
=output voltage
×
0.4 to
×
0.6
I
OUT
=10
µ
A to I
OUT
(below)
×
1.25
S-8321AMMP
S-8321AAMP
S-8321AFMP
S-8321AGMP
Ta=- 40
°
C to+85
°
C
S-8321AIMP
S-8321ALMP
S-8321AJMP
S-8321AOMP
V
OUT
=output voltage
×
0.95
Measure waveform at CONT pin
Min.
5.368
4.880
3.416
3.221
2.928
2.635
2.440
2.147
99
99
82
68
68
53
53
39
90
Typ.
5.500
5.000
3.500
3.300
3.000
2.700
2.500
2.200
Max.
5.632
5.120
3.584
3.379
3.072
2.765
2.560
2.253
9
0.9
0.8
15.6
15.0
12.0
11.7
11.4
11.4
11.1
10.8
78.3
71.4
50.9
48.1
44.0
40.0
37.2
33.1
4.6
4.4
4.0
3.9
3.8
3.8
3.7
3.6
0.5
1.0
Unit
Test
circuit
Output voltage
V
OUT
1
V
Input voltage
Operation start voltage
Oscillation start voltage
V
IN
V
ST1
V
ST2
2
Input voltage at no load
I
IN
Current consumption 1
I
SS1
Current consumption 2
I
SS2
Shutdown current
I
SSS
Switching current
I
SW
9.4
9.0
7.2
7.0
6.8
6.8
6.7
6.5
54
49
31
29
26
24
22
20
2.8
2.6
2.4
2.3
2.3
2.3
2.2
2.2
148
148
122
102
102
80
80
58
µ
A
2
mA
Switching transistor
leak current
CONT limit voltage
Line regulation
Load regulation
I
SWQ
V
CONT LMT
V
OUT1
V
OUT2
µ
A
Output voltage
temperature coefficient
V
OUT
/ Ta
Oscillation frequency
fosc
0.9
30
30
±
0.28
±
0.25
±
0.18
±
0.17
±
0.15
±
0.14
±
0.13
±
0.11
100
V
60
mV
60
±
1.40
±
1.25
±
0.90
±
0.85
mV/ C
±
0.75
±
0.70
±
0.65
±
0.55
110
KHz
1
2
Seiko Instruments Inc.
3
SMALL PACKAGE PFM CONTROL STEP-UP SWITCHING REGULATOR
S-8321/8322 Series
( Unless otherwise specified: Ta=25
°
C )
Parameter
Duty ratio 1
Duty ratio 2
Symbol
Duty1
Duty2
V
SH
Shutdown pin
input voltage
V
SL1
V
SL2
Conditions
V
OUT
=output voltage
×
0.95
Measure waveform at CONT pin
Min.
70
Typ.
75
50
Max.
80
Unit
%
Test
circuit
2
Efficiency
EFFI
V
OUT
=output voltage
×
0.95
0.75
Judge the oscillation at CONT pin
When
V
OUT
=output voltage
×
0.95
V
OUT
≥
1.5V
Judge the stop at CONT pin When
V
OUT
<1.5V
S-8321AMMP
S-8321AAMP
S-8321AFMP
S-8321AGMP
S-8321AIMP
S-8321ALMP
S-8321AJMP
S-8321AOMP
0.3
0.2
V
2
85
85
80
80
80
70
70
70
%
1
External parts used:
- Coil
CD54 (100
µ
H) of Sumida Electric Co., Ltd.
- Diode
MA729 (schottky type) of Matsushita Electronic Components Co., Ltd.
- Capacitor F93 (16 V, 22
µ
F, tantalum type) of Nichicon Corporation
V
IN
=output voltage
×
0.6 applied, I
OUT
=output voltage / 250
Ω
Note: Output voltage specified above is the typical value of the output voltage.
4
Seiko Instruments Inc.
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