Contents
Features ...........................................................1
Applications......................................................1
Block Diagram..................................................1
Pin Assignment ................................................2
Absolute Maximum Ratings .............................2
Electrical Characteristics..................................2
UC
T
Test Circuits .....................................................3
Operation .........................................................4
Selection of External Parts...............................6
OD
Standard Circuits..............................................9
Application Circuit ............................................9
Notes on Design.............................................10
DI
SC
ON
TI
NU
E
D
Dimensions, Taping .......................................14
PR
Characteristics ...............................................11
Rev.2.0
S-8437/8438 Series
INVERTING SWITCHING REGULATORS
UC
T
The S-8437/8438 Series is a CMOS inverting switching regulator that
consists of a reference voltage source, a CR oscillation circuit, a power
MOS FET and an error amplifier. For the S-8437AF, the output voltage
is fixed internally and it easily forms an inverting switching regulator with
shutdown function; using an external coil, a diode and a capacitor. For
the S-8438AF, any output voltage can be set under the condition of
VIN≤20-|-VOUT| by mounting two external resistors in addition to the
external coil, diode, and capacitor. Both are suitable for use as power
sources for portable devices because of their small 5-pin package
(SOT-89-5), low current consumption and few external parts.
•
•
•
n Block Diagrams
1. S-8437AF
−VOUT
ON
TI
CONT
VIN
PR
•
D
•
• Power supply for portable equipment, such as pagers,
electronic calculators, and remote controllers
• Constant voltage power for LCDs and analog circuits
• Power supply for communications equipment, such as
cordless phone and portable telephone
Low current consumption: (S-8437AF)
Operation : 13 µA typ.
Shutdown : 0.1 µA max.
High-precision output voltage:
-5 V±3.5%(S-8437AF)
Any voltage can be set by mounting two
external resistors (S-8438AF).
Built-in CR oscillation circuit:
Oscillation frequency: 50 kHz typ.
Built-in power MOS FET
5-pin SOT-89-5 small package
NU
E
•
n Applications
OD
n Features
2. S-8438AF
CONT
VIN
M1
M1
R1
Control
circuit
Control
circuit
+
−
Oscillation
circuit
Reference
voltage circuit
Reference
voltage circuit
VFB
VREF
VSS
VSS
DI
ON/OFF
SC
R2
Oscillation
circuit
+
−
Figure 1
Seiko Instruments Inc.
1
INVERTING SWITCHING REGULATORS
S-8437/8438 Series
n Pin Assignment
Table 1
Top view
4
Terminal
name
1
2
S-8437
S-8438
CONT
VSS
ON/OFF
VFB
3
-VOUT
VREF
4
1
2
3
5
VIN
Description
Power MOS FET drain terminal
Ground terminal
ON/OFF : Shutdown input terminal
VFB : Feedback voltage input terminal
-VOUT : Negative output voltage
terminal
VREF : Reference voltage output terminal
Positive power input voltage terminal
UC
T
5
Figure 2
Table 2
OD
n Absolute Maximum Ratings
(Unless otherwise specified : Ta=25°C)
Unit
13
VSS-0.3 to VIN+0.3
VIN ≤20-|-VOUT|
700
500
-40 to+85
-40 to+125
V
V
V
mA
mW
°C
°C
PR
VIN
Vterm
-VOUT
ICONT
PD
Topr
Tstg
Rating
VFB, ON/OFF
NU
E
Input power voltage
Input terminal voltage
Output terminal voltage
CONT output current
Power dissipation
Operating temperature
Storage temperature
Applicable
terminal
Symbol
D
Parameter
n Electrical Characteristics
1. S-8437AF-ZA-X
Parameter
Symbol
Min.
(Unless otherwise specified : Ta=25°C)
Typ.
Max.
Unit Test cir.

-5.000
35
20
±0.38
10
-5.175
160
100

VIN=5 V, VOUT=-7 V
VIN=5 V, ON/OFF=L
VIN=5 V
VIN=5 V, CONT=4 V
VIN=5 V, ON/OFF=H


30

2.4
13

50
150
28
0.1
70


VSL VIN=5 V, ON/OFF=L
VOUTOF VIN=5 V, ON/OFF=L
RL=100 Ω




DI
Output voltage during
shutdown
Conditions
2
-4.825



VIN
-VOUT
∆VOUT1
∆VOUT2
∆VOUT
∆Ta
ISS
IST
fOSC
ISW
VSH
SC
Input power voltage*
Output voltage**
Line regulation
Load regulation
Output voltage
temperature coefficient
Current consumption
Current during power-off
Oscillation frequency
Switching current
Shutdown input terminal
input voltage
ON
TI
Table 3
VIN=5 V, IOUT=10 mA
VIN=3 to 10 V, IOUT=10 mA
VIN=5 V, IOUT=10 µA to 15 mA
Ta=-40°C to+85 C
* The following equation shall be met: VIN ≤20- |-VOUT|
** External parts:
Coil: RCH654-101K (100µH) manufactured by Sumida Electronics, or equivalent
Diode: DINS4 manufactured by Shindengen, or equivalent
If you need output voltages other than above, contact our Sales Department.
2
Seiko Instruments Inc.

V
V
mV
mV
mV
/°C
µA
µA
kHz
mA
V
1
1
1
1
1
2
2


2
0.4
0.1
V
V
2
1
INVERTING SWITCHING REGULATORS
S-8437/8438 Series
2. S-8438AF-ZB-X
Table 4
(Unless otherwise specified : Ta=25°C)
Parameter
Symbol
VIN
∆VOUT1 VIN=3 to 10 V, VOUT=-5 V
IOUT=10 mA
∆VOUT2 VIN=5 V, VOUT=-5 V
IOUT=10 µA to 15 mA
VREF VIN=5 V
∆VREF Ta=-40°C to+85°C
∆Ta
ISS
VIN=5 V, VFB=-0.3 V
fOSC
VIN=5 V
ISW
VIN=5 V, CONT=4 V
Load regulation
Reference voltage
Reference voltage
temperature coefficient
Current consumption
Oscillation frequency
Switching current
Min.
Typ.
Max.
Unit
Test cir.
2


35
10
160
V
mV
3
3

20
100
mV
3
1.176

1.200
±0.07
1.224

4
4

30

9
50
150
19
70

V
mV /
°C
µA
kHz
mA
UC
T
Input power voltage*
Line regulation
Conditions
OD
* The following equation shall be met: VIN≤20- |-VOUT|
4


1.
22µF
CONT
S-8437AF
ON/OFF
VSS
+
22µF
100µF
V
2.
VIN
NU
E
D
-
-VOUT
VIN
+
PR
n Test Circuits
-VOUT
S-8437AF
A
-7 V
(Do NOT apply -7 V when measuring ISSS)
VSS
ON
TI
ON/OFF
SC
3.
+
R2
VREF
S-8438AF
22µF
R1
VFB
VIN
220 pF
CONT
R1=417 kΩ, R2=100 kΩ
-
VSS
+
100 µF
DI
-
* Do NOT connect a capacitor to the input
side.
22µF
V
4.
VIN
A
VFB
S-8438AF
-0.3 V
VREF
VSS
V
* Do NOT connect a capacitor to the input
side.
Figure 3
Seiko Instruments Inc.
3
INVERTING SWITCHING REGULATORS
S-8437/8438 Series
n Operation
The S-8437/8438 Series consists of a power MOS FET (M1) and a CR oscillation circuit. M1 is turned on and off by the CR
oscillation circuit. When M1 is on (tON), energy is accumulated in the inductor (L). When M1 is off (tOFF), the accumulated energy
is transferred to the -VOUT capacitor (COUT) through the diode.
CR oscillation circuit :
Oscillator by a capacitor and a resistor. The oscillating frequency is 50 kHz typ.
Reference voltage circuit : Can obtain the reference voltage output of 1.2 V ±2%.
In the S-8437/8438 Series, the switching transistor consists of a large Pch power MOS FET. The MOS
FET enables much higher-speed switching than a bipolar transistor. The MOS FET can be driven with
gate charge and discharge currents. Thus a high-efficient DC-DC converter with few switching losses
and low power consumption can be made.
UC
T
Power MOS FET M1 :
Shutdown terminal (S-8437AF only) : The reference voltage circuit and CR oscillation circuit can be stopped or started by turning
the shutdown terminal to L or H. The input voltage level can meet the TTL level (L:0.4 V
max., H:2.4 V min.).
Table 5
Description
OD
ON/OFF
All circuit currents are disconnected when oscillation stops (0.1 µA max.).
Reversal booster operation.
“L”
“H”
PR
NOTE: Do NOT use the shutdown terminal in the floating status.
Voltage at A when M1 is on (current IL flowing in L is zero):
VA=VIN−VS .................................................................(1)
Change by time of IL:
dIL
dt
=
VL
L
VIN−VS
=
L
ON
TI
VIN−VS
• t ..................................... (3)
L
M1
A
VIN
L
............................ (2)
Integral (IL) of the above equation:
IL=
NU
E
(VS : M1 non-saturation voltage)
D
The basic equations of the inverting switching regulators are shown below.
Di
−
+
−VOUT
COUT
OSC
Figure 4
Inverting switching regulator
This IL flows at tON. This time is determined by the OSC oscillation frequency.
SC
Peak current (IPK) in tON:
VIN−VS
IPK=
• tON ........................................(4)
DI
L
In this case, the energy accumulated in L is indicated by 1/2L • (IPK)2.
Then, when M1 is off, the energy accumulated in L is transferred to the ground, capacitor, and diode (Di), and a reverse voltage
(VL) is generated.
VL is as follows:
VL=−(VOUT+VD)............................................ (5)
(VD : Forward voltage of diode Di)
4
Seiko Instruments Inc.
INVERTING SWITCHING REGULATORS
S-8437/8438 Series
Change by the time of IL that flows to−VOUT through the capacitor at tOFF:
dIL
dt
=
VL
VOUT+VD
=
L
................................(6)
L
Integral of the above equation:
IL=IPK −
VOUT+VD
• t............................(7)
L
In tON, energy is accumulated in L and is not transferred to VOUT. Capacitor (COUT) energy is used for a load current (IOUT) from−VOUT.
UC
T
As a result, COUT terminal voltage decreases, and this voltage becomes a minimum in tON. If M1 is off, the energy accumulated in L is
transferred to COUT through the diode, and COUT terminal voltage increases rapidly. VOUT voltage indicates a maximum value (ripple
voltage: VPP) when the current that flows to VOUT through the diode matches the constant load current IOUT.
Then this ripple voltage is derived.
OD
IOUT when t1 is the time period until VOUT reaches the maximum value after tON:
VOUT+VD
• t1................................................................................... (8)
L
L ........................................................................... (9)
∴ t1= (IPK−IOUT) •
VOUT+VD
PR
IOUT = IPK −
Considering IL=0 occurs (all inductor energy is transferred) in tOFF, equation (7) becomes:
L
VOUT+VD
tOFF
............................. (10)
IPK
D
=
IOUT
IPK
t1=tOFF−
NU
E
Substituting (10) into (9) :
• tOFF ............................... (11)
The amount of charge Q1 charged in COUT at t1:
∆Q1 = ∫
t1 I
OUTdt=IPK
0
L
VOUT+VD
L
•
• ∫ t1 tdt
0
1 t12 ...................... (12)
2
ON
TI
=IPK•t1 −
Substituting (12) into (9):
∆Q1=IPK−
VOUT+VD
• t1 −
1
(IPK−IOUT) • t1=
2
IPK+IOUT
• t1 ................ (13)
2
VPP =
SC
The voltage (VPP) that is raised by ∆Q1:
∆Q1
COUT
=
1
COUT
•
IPK+IOUT
2
• t1 ............... (14)
IPK+IOUT
2
• t1−
DI
When IOUT consumed for t1 is considered:
VPP =
∆Q1
COUT
=
1
COUT
•
•
tOFF
COUT
IOUT • t1
........ (15)
COUT
Substituting (11) into (15):
VPP =
(IPK−IOUT)2
2IPK
.......................... (16)
Seiko Instruments Inc.
5
INVERTING SWITCHING REGULATORS
S-8437/8438 Series
n Selection of External Parts
1. Inductor
To reduce the loss due to the DC resistance, select an inductor with as small a DC resistance as possible (less than 1 Ω).
Select the best inductance for the application.
To make the average value of the output voltage (−VOUT) constant, the inductor must supply energy equivalent to the output
current (IOUT). The amount of charge required for IOUT is IOUT × (tON+tOFF). The inductor can supply energy only during tOFF,
thus the amount of charge is obtained as IPK/2 × tOFF by integrating equation (7) by 0→tOFF. Therefore:
UC
T
IPK • t =I × (t +t )
..........................................................(17)
OFF OUT
ON OFF
2
tON+tOFF
∴ IPK=2 •
• IOUT ............................................................................. (18)
tOFF
Since the oscillation duty ratio of the OSC is 50% and IPK equals 4 × IOUT if tON=tOFF, the IPK current flowing in the transistor must
be four times of IOUT. IPK is limited due to the characteristics of the M1 transistor (700 mA max.).
OD
In the S-8437/8438 Series, 39 to 820 µH of inductance is recommended.
Using an inductor with a small L value increases IPK and IOUT. Accordingly, the minimum operating voltage is lowered, but
efficiency decreases. This state is shown in Figures 5 to 7.
D
PR
Using an inductor with a large L value decreases IPK and IOUT. Since the energy accumulated in the inductor is (½)•L(IPK)2, IPK
decreases in steps of squares offsetting the increase of L, and the energy decreases overall. Accordingly, stepping up at low
voltages is difficult and the minimum operating voltage must be specified as a high value. However, the DC resistance loss in L
and the M1 transistor becomes small because of the reduced IPK, and the efficiency is improved overall. As indicated in the
equation (16), the ripple voltage can be reduced by decreasing IPK. Figures 8 to 10 show the output voltage waveforms when the
L value and COUT value are changed.
VIN=10 V
ON
TI
VIN=5 V
Conditions : S-8437AF
−VOUT=−5 V
Coil
:RCH654
(Sumida Electronic)
Diode :DINS4
(Shindengen)
VIN=3 V
SC
100
90
80
70
60
IOUT (max)
50
(mA)
40
30
20
10
0
10
NU
E
Note Too large an IPK causes magnetic saturation depending on the core material, resulting in destruction of the IC chip.
Always keep Isat higher than IPK (Isat: level of current that causes magnetic saturation).
100
Inductor value (µH)
1000
DI
Figure 5 Inductor value − maximum output current *
6
Seiko Instruments Inc.
INVERTING SWITCHING REGULATORS
S-8437/8438 Series
70
20
Conditions : S-8438AF
VIN=5 V
R2=100 kΩ fixed
R1=0.6 to 1.5 MΩ variable
Coil
:RCH654
(Sumida
Electronic)
Diode : DINS4
(Shindengen)
10
L=100 µH
60
L=47 µH
50
40
30
0
−5
L=470 µH
−6
−7
−8
−9
−10 −11 −12 −13 −14 −15
−VOUT (V)
UC
T
IOUT (max)
(mA)
PR
Conditions : S-8437AF
VIN=5 V
IOUT=10 mA
Coil:
RCH654
(Sumida Electronic)
Diode : DINS4
(Shindengen)
D
NU
E
Power
coefficiency
(%)
100
90
80
70
60
50
40
30
20
10
0
10
OD
Figure 6 Output voltage − maximum output current *
100
Inductor value (µH)
1000
Figure 7 Inductor value − power efficiency
2. Diode
ON
TI
* The maximum output current (IOUT(MAX)) is defined as the output current (IOUT) when an output voltage (−VOUT2) can be obtained
that is 325 mV lower than the output voltage (−VOUT1) when the output current (IOUT) is 10µA.
SC
Use the external diode that meets the following conditions :
• Low forward voltage (VF<0.3 V)
• Fast switching rate (500 ns max.)
• Backward voltage of VIN +|− VOUT| or more
• Current rating of IPK or more
DI
3. Capacitors (CIN and COUT)
The input capacitor (CIN) reduces power source impedance and stabilizes the input current to improve the efficiency. Select
a CIN value depending on the impedance of the power source used. The capacitor value is 10 µF min.
Select a large output capacitor (COUT) with small Equivalent series resistance (ESR) for reducing ripple voltage. As indicated
in the equation (16), if the capacitor value is increased, the ripple voltage can be reduced (see the next page). Its capacitor
value is 22 µF min. A tantalum electrolytic capacitor or an organic semiconductor capacitor is recommended to be used
because of their excellent low temperature and leakage current characteristics.
Seiko Instruments Inc.
7
INVERTING SWITCHING REGULATORS
S-8437/8438 Series
(a) COUT=22 µF, L=100 µH
Ta=25°C
Conditions:
VIN=5V
IOUT=10 mA
Coil : RCH654-101K
(100 µH)
UC
T
Output
50 mV/div −5 V
t (500 µs/div)
Figure 8
OD
(b) COUT=47 µF, L=100 µH
Ta=25°C
PR
Conditions:
VIN=5 V
IOUT=10 mA
Coil : RCH654-101K
(100 µH)
NU
E
D
Output
50 mV/div −5 V
t (500 µs/div)
Figure 9
Ta=25°C
Conditions:
VIN=5 V
IOUT=10 mA
Coil : RCH654-471K
(470 µH)
DI
SC
Output
50 mV/div −5 V
ON
TI
(c) COUT=22 µF, L=470 µH
8
t (100 µs/div)
Figure 10
Seiko Instruments Inc.
INVERTING SWITCHING REGULATORS
S-8437/8438 Series
n Standard Circuits
1. S-8437AF
−VOUT
VIN
+
22 µF
ON
−
S-8437AF
ON/OFF
−VOUT
CONT
−
22 µF
+
VSS
OFF
100 µH
2. S-8438AF
R2
UC
T
Figure 11
R1
100 kΩ
VREF
+
22 µF
VFB
OD
VIN
417 kΩ
220 pF
S-8438AF
CONT
−
PR
VSS
+
−VOUT
22 µF
100 µH
−VOUT=− R1 ×1.2 V
R2
D
Figure 12
−
NU
E
n Application Circuit
CONT
VIN
+
Voltage
detection
circuit
ON
TI
−
VOUT
S-8437AF
LCD power
−
+
ON/OFF
VSS
CE
Figure 13 When the current consumption is decreased
DI
SC
microcomputer
Seiko Instruments Inc.
9
INVERTING SWITCHING REGULATORS
S-8437/8438 Series
n Notes on Design
1. Common for S-8437/8438AF
600
• Mount the external capacitor, diode, and coil as close to the
ICs as possible to reduce the DC resistance.
• Take short-circuiting and overheating into consideration
during design because no short-circuit or overheat protection
circuits and loaded in the S-8437/8438AF. As reference,
Figure 14 shows the package power dissipaiton when
unmounting at an ambient temperature.
400
Power
dissipation
PD
200
(mW)
UC
T
0
150
VIN
S-8437AF
0
50
100
Ambient temperature Ta (°C)
Figure 14 Package power dissipation
(when not mounted)
OD
2. S-8437AF
NU
E
D
PR
• If the ON/OFF terminal is connected to the VIN terminal, confirm that the
fluctuation of the VIN terminal voltage is higher than the VSL level of the
ON/OFF terminal. If the voltage fluctuation is lower than the VSL level,
the power is turned off and the output voltage is decreased. In this case,
insert a filter circuit into the ON/OFF terminal, as shown in Figure 15.
3. S-8438AF
+
−
ON/OFF
VSS
Figure 15
DI
SC
n
ON
TI
• If two external resistors are used, keep them as far away as possible from the coil and CONT terminal to prevent noise. In
particular, if noise enters the VFB terminal, the line regulation will deteriorate.
• Set the resistance values as follows:
R1 : 2 MΩ or less
R2 : 10 to 500 kΩ
• The line regulation may be improved by adding the capacitor in parallel with the R1 resistor (in particular, IOUT≥20 mA
application at VIN≥7 V). The capacitor value (CC) shall be R1 • CC≅4µs.
10
Seiko Instruments Inc.
INVERTING SWITCHING REGULATORS
S-8437/8438 Series
n
n Characteristics
2. Shutdown terminal input voltage (VSH, VSL) −
ambient temperature (Ta)
1. Operating current consumption (ISS)
− ambient temperature (Ta)
VIN=5 V, VFB=−0.1 V
20
15
VSH, VSL
(V)
ISS
10
(µA)
0
−50
0
50
70
60
50
fOSC 40
(kHz) 30
20
10
0
−50
VSL
0.5
4
6
VIN (V)
8
10
0
50
100
D
Ta (°C)
NU
E
5. Oscillation frequency duty
− ambient temperature (Ta)
VIN=5 V
70
60
ON
TI
20
−50
PR
VSH
30
100
VIN=5 V
OD
1.5
VSH, VSL
1.0
(V)
Duty 50
(%)
40
50
4. Oscillation frequency (fOSC)
− ambient temperature (Ta)
Ta=25°C
2.0
2
0
Ta (°C)
3. Shutdown terminal input voltage (VSH, VSL) −
input voltage (VIN)
0
VSL
−50
100
Ta (°C)
0
VSH
UC
T
5
VIN=5 V
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0
50
100
6. Oscillation frequency (fOSC)
− input voltage (VIN)
55
50
45
fOSC 40
(kHz) 35
30
25
20
Ta (°C)
Ta=25°C
0
2
4
6
8
10
12 14
VIN (V)
Ta=25°C
DI
Duty
(%)
80
75
70
65
60
55
50
45
40
SC
7. Oscillation frequency duty
− input voltage (VIN)
0
2
4
6
8
10
12 14
VIN (V)
Seiko Instruments Inc.
11
INVERTING SWITCHING REGULATORS
S-8437/8438 Series
8. Output voltage (−VOUT)
− output current (IOUT)
Coil : RCH654-101K (100µH)
(Sumida Electronic)
(b) Ta=25°C
(a) Ta=−40°C
−5.5
−5.5
−VOUT
(V)
VIN=10 V
−4.5
0.1
VIN=3 V
1
−5.0
VIN=3 V
VIN=5 V
10
VIN=10 V
−4.5
0.1
100
(c) Ta=85°C
−VOUT
(V) −5.0
100
VIN=3 V
VIN=5 V
10
100
IOUT (mA)
9. Maximum output current (IOUT(max))
− ambient temperature (Ta)
PR
VIN=10 V
NU
E
D
Coil : RCH654
(Sumida Electronic)
−VOUT=−5 V
100
VIN=5V
IOUT (max)
(mA)
A
L=47 µH
50
ON
TI
VIN=3V
0
−50
10
OD
−5.5
1
1
IOUT (mA)
IOUT (mA)
−4.5
0.1
VIN=5 V
UC
T
−VOUT
(V) −5.0
0
50
B
L=100 µH
100
Ta (°C)
Maximum output current (IOUT(max))
− output voltage (−VOUT) (S-8438 only)
11. Temperature characteristics in 10
SC
10.
DI
R2=100 kΩ, R1=0.6 to 1.5 MΩ
VIN=20 V−|−VOUT |
100 L=47, 100µH (RCH654), Ta=25 °C
IOUT (max)
(mA)
R2=100 kΩ, R1=0.6 to 1.5 MΩ
VIN=20 V−|−VOUT |
L=47µH
(RCH654)
100
Ta=•|40
(°C)Ta=25 (°C)
Ta=85 (°C)
IOUT (max)
(mA)
50
L=47µH
50
L=100µH
0
−5
−10
−15
−20
−VOUT (V)
12
0
−5
−10
−15
−VOUT (V)
Seiko Instruments Inc.
−20
INVERTING SWITCHING REGULATORS
S-8437/8438 Series
12. Maximum output current * (IOUT(max))
− inductor value (L) (S-8438AF)
12-1. Sumida Denki RCH654 series
R2=100 kΩ, R1=417 kΩ
VIN=3, 5, 10 V
−VOUT=−5 V, Ta=25°C
VIN=5V
100
IOUT (max)
(mA)
50
VIN=10V
50
VIN=3V
0
10
100
0
10
1000
VIN=10V
100
1000
L (µH)
OD
13. Transient response characteristics
13-2.
IOUT=10 mA
COUT=22 µF, Ta=25°C
Coil : RCH654-101K
Diode : D1NS4
PR
VIN step response characteristics
(VIN=0↔5 V)
VIN step response characteristics
(VIN=0↔10 V)
IOUT=10 mA
COUT=22 µF, Ta=25°C
Coil : RCH654-101K
Diode : D1NS4
Input
5 V/div
GND
GND
Output
2 V/div
ON
TI
t (10 ms/div)
NU
E
D
Input
5 V/div
GND
VIN=5V
VIN=3V
L (µH)
13-1.
R2=100 kΩ, R1=417 kΩ
VIN=3, 5, 10 V
−VOUT=−5 V, Ta=25°C
UC
T
100
IOUT (max)
(mA)
12-2. TDK chip coil NLC453232 series
13-3. Shutdown terminal step response
characteristics (ON/OFF=0↔5 V)
t (10 ms/div)
13-4. Load current fluctuation response
characteristics (IOUT=10µA↔15 mA)
VIN=5 V, COUT=22 µF
Ta=25°C
Coil : RCH654-101K
Diode : D1NS4
IOUT=10 mA, VIN=5 V
COUT=22 µF, Ta=25°C
Coil : RCH654-101K
Diode : D1NS4
SC
ON/OFF
input
5 V/div
GND
GND
Output
2 V/div
DI
GND
Output
2 V/div
10 µA
Load current
15 mA
GND
Output
2 V/div
t (10 ms/div)
t (10 ms/div)
Seiko Instruments Inc.
13
UP005-A 990531
SOT-89-5
Unit
mm
Dimensions
4.5±0.1
1.5±0.1
1
2
UC
T
1.6±0.2
3
1.5±0.1 1.5±0.1
ON
TI
0.45±0.1
Taping Specifications
ø1.5 +0.1
-0
4.0±0.1(10 pitches 40±0.2)
ø1.5 +0.1
-0
8.0±0.1
DI
5 max.
SC
2.0±0.05
0.3
45
NU
E
0.4±0.1
0.4±0.1
D
PR
OD
0.4±0.05
Reel Specifications
1 reel holds 1000 ICs.
3 max.
0.3±0.05
2.0±0.1
4.75±0.1
ø21±0.5
ø13±0.2
2±0.2
Feed direction
8437
Markings
SOT-89-5
4
OD
UC
T
5
2
DI
SC
ON
TI
NU
E
D
PR
1
3
990603
UC
T
OD
PR
D
NU
E
ON
TI
SC
•
•
DI
•
•
The information herein is subject to change without notice.
Seiko Instruments Inc. is not responsible for any problems caused by circuits or other diagrams
described herein whose industrial properties, patents or other rights belong to third parties. The
application circuit examples explain typical applications of the products, and do not guarantee any
mass-production design.
When the products described herein include Strategic Products (or Service) subject to regulations,
they should not be exported without authorization from the appropriate governmental authorities.
The products described herein cannot be used as part of any device or equipment which influences
the human body, such as physical exercise equipment, medical equipment, security system, gas
equipment, vehicle or airplane, without prior written permission of Seiko Instruments Inc.