EPSON SCI7661

PF110-10
SCI7661COA/MOA
DC-DC Converter
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lta
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V n
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Lo pera cts
O rodu
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● 95% Typical Power Efficiency
● Doubled or Tripled Output Voltage
● Internal Voltage Regulator
■ DESCRIPTION
The SCI7661COA/MOACMOS DC-DC Converter features high operational performance with low power dissipation.
It consists of two major parts: the booster circuitry and the regulator circuitry. The booster generates a doubled
output voltage (–2.4 to –12V) or tripled output voltage (–3.6 to –18V) from the input (–1.2 to –6V). The regulator is
capable of setting the output to any desired voltage. The regulated voltage can be given one of the three threshold
temperature gradients.
■ FEATURES
● High performance with low power dissipation
● Simple conversion of VIN (–5V) to |VIN| (+5V),
2 |VIN| (+10V), 2VIN (–10V) or 3VIN (–15V)
● On-chip output voltage regulator
● Power conversion efficiency–Typ. 95%
● Temperature gradient for LCD power supply – 0.1% / °C, 0.4%/°C or 0.6%/ °C
● Power off by external signals – Stationary current at power off – Max. 2 µA
● Cascade connection–two device connected:
VIN=–5V, VOUT=–20V
● On-chip C'–R oscillator
● Package .................................... SCI7661C0A: DIP-14pin (plastic)
SCI7661M0A: SOP5-14pin (plastic)
SCI7661MAA: SSOP2-16pin (plastic)
■ BLOCK DIAGRAM
VIN
Voltage
Converter
(I)
CAP2–
CAP2+
Voltage
Converter
(II)
T
CAP1–
CAP1+
Temperature Gradient
Select Circuit
CR
Oscillator
Voltage Regulator
OSC1
OSC2
Reference Voltage
Generator
VDD
TC1
TC2
Poff
RV
Vreg
Vout
Booster
Regurator
SCI7661COA/MOA
■ PIN CONFIGURATION
■ PIN DESCRIPTION
CAP1+
1
14
VDD
CAP1-
2
13
OSC1
CAP2+
3
12
OSC2
CAP2-
4
11
Poff
TC1
5
10
RV
TC2
6
9
Vreg
VIN
7
8
Vout
Pin name
CAP1+, CAP1CAP2+, CAP2TC1, TC2
VIN
No.
1, 2
3, 4
5, 6
7
Terminal for connection of capacitor for doubler
Terminal for connection of capacitor for tripler
Temperature gradient selection terminal
Power supply terminal(negative, system supply
GND)
8
Output terminal at tripling
9
Regulated voltage output terminal
10
Regulated voltage control terminal
11
Vreg output ON/OFF control terminal
12, 13 Oscillation resistor connection terminal
14
Power supply terminal(positive system supply
VCC)
VOUT
Vreg
RV
Poff
OSC2, OSC1
VDD
The same pin configuration in
DIP and SOP
Function
■ ABSOLUTE MAXIMUM RATINGS
Rating
(VDD=0V)
Min.
Symbol
Input supply voltage
VI
Input terminal voltage
VI
Output voltage
VO
Allowable loss
Pd
Remark
Unit
Max.
-20/N
0.5
V
N=2 : Doubler
N=3 : Tripler
VIN-0.5
0.5
V
OSC1, Poff
VOUT-0.5
-20.0
0.5
V
V
TC1, TC2, RV
300
mW
Operating temperature
Topr
-30
85
°C
Storage temperature
Tstg
-55
150
°C
Soldering temperature and time
Tsol
260°C, 10s(at lead)
Plastic package
-
Note: When this IC is soldered in the solder-reflow process, be sure to maintain the reflow furnace at the curve shown in "Fig.
1-5 Reflow Furnace Temperature Curve" of this DATA BOOK. And this IC can not be exposed to high temperature of
the solder dipping.
■ ELECTRICAL CHARACTERISTICS
(VDD = 0V, VIN=-5V, Ta=-30 to 85°C)
Characteristic
Symbol
Min.
VI
-6.0
VO
-18.0
Vreg
-18
-2.6
V
Regulator operating voltage
VOUT
-18.0
-3.2
V
Booster current consumption
Iopr1
100
µA
RL=∞, ROSC=1MΩ
12.0
µA
RL=∞, RRV=1MΩ
VOUT=-15V
2.0
µA
TC2=TC1=VOUT, RL=∞
20
24
kHz
ROSC=1MΩ
150
200
Ω
IOUT=10mA
Input supply voltage
Typ.
Max.
Unit
-1.2
V
V
Output voltage
Regulator current
consumption
Iopr2
Stationary current
IQ
Oscillation frequency
2
fosc
Output impedance
ROUT
Booster power conversion
efficiency
Peff
Regulated output voltage
fluctuation
∆Vreg
∆VOUT•Vreg
60
50
16
90
Condition
95
%
0.2
%/V
RL=∞, RRV=1MΩ,
VO=-18V
IOUT=5mA
-18V<VOUT<-8V,
Vreg=-8V, RL=∞, Ta=25°C
SCI7661COA/MOA
Characteristic
Symbol
Min.
Typ.
Max.
Unit
Condition
∆Vreg
∆IOUT
5
Ω
VOUT=-15V, Vreg=-8V,
Ta=25°C
0<IOUT<10mA, TC1=VDD
TC2=VOUT
Regulated output saturation
resistance
RSAT
5
Ω
RSAT=D(Vreg—VOUT)/DIOUT
0<IOUT<10mA, RV=VDD,
Ta=25°C
Reference voltage
VRV0
VRV1
VRV2
-2.3
-1.7
-1.1
-1.5
-1.3
-0.9
-1.0
-1.1
-0.8
V
V
V
TC2=VOUT, TC1=VDD, Ta=25°C
TC2=TC1=VOUT, Ta=25∞C
TC2=VDD, TC1=VOUT, Ta=25°C
Temperature Gradient
CT0
CT4
CT2
-0.25
-0.5
-0.7
-0.1
-0.4
-0.6
-0.06
-0.3
-0.5
%/°C
%/°C
%/°C
2.0
µA
Regulated output load
fluctuation
IL
Input leakage current
| Vreg(50°C) | - | Vreg(0°C) |
50°C-0°C
1
×100
| Vreg(25°C) |
CT =
×
Poff, TC1, TC2, OSC1, RV pins
■ RECOMMENDED OPERATING CONDITIONS
Condition
Symbol
Min.
(Ta=-30 to 85°C)
Max.
Unit
V
Remark
ROSC=1MΩ, C3≥10µF*1
CL/C3≤1/20, Ta=-20 to 85°C
ROSC=1MΩ
-1.2
V
-1.2
-2.2
V
ROSC=1MΩ
Min.*2
Ω
VSTA1
Booster start voltage
VSTA2
VSTP
Booster stop voltage
RL
Output load resistance
RL
Output load current
IOUT
20
mA
Oscillation frequency
Extarnal resistance for
oscillation
Capasitor for booster
Regulated output adjustable
resistance
fOSC
10
30
kHz
ROSC
680
2000
kΩ
C1, C2, C3
3.3
RRV
100
µF
1000
*1: Recommended circuity in low voltage operation is
shown below.
kΩ
*2: RL Min. depends on input voltage as shown below.
(VIN=-1.2V ~ -2.2V)
5
+ 1
-
14
13
12
11
10
9
8
2
+ 3
4
C2=10µF
5
6
7
VSTA2
VSTA1
4
ROSC=
1MΩ
RL
CL
RL Min.(kΩ)
=C1=10µF
3
2
1
Triple
+ C3=22µF
D1(VF(IF=1mA))
0
≤ 0.6v
Double
0
1.5 2
3
4 5 6
VIN(V)
3
SCI7661COA/MOA
■ PERFORMANCE CURVES
fOSC(kHz)
fOSC(kHz)
VIN=-5V
VIN=-3V
VIN=-1.5V
100
30
20
10
1
10K
100K
680K1M
150
26
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
–30
10M
Ta=25°C
fOSC=40kHz
VIN=-5V
100
Iopr1(µA)
1000
VIN=-3V
fOSC=20kHz
VIN=-1.5V
50
fOSC=10kHz
50
0
100
150
0
1
2
3
Ta(°C)
ROSC(Ω)
Fig.1 Oscillation Frequency(fOSC)vs.
External-Resistance(ROSC)
Fig.2 Oscillation Frequency(fOSC)vs.
Temperature(Ta)
4
5
VIN(V)
6
7
Fig.3 Input Voltage(VIN)vs. Booster
Current Consumption(Iopr1)
400
0
Ta=25°C
VIN=-5V
300
VOUT(V)
-2
Double
-3
-5
Triple
-6
Triple
0
1
2
3
4
5
6
7
8
9
10
0
0
50
Fig.4 Output Voltage(VOUT)vs.
Output Current(IOUT)
Fig.5 Output Voltage(VOUT)vs.
Output Current(IOUT)
100
100
100
90
90
90
80
80
Double
Peff
70
80
60
60
50
50
Triple
IIN
40
Triple Peff
30
Double IIN
20
10
0
0
10
20
30
IOUT(mA)
40
40
30
30
20
20
10
10
0
0
50
24
60 I =20mA
OUT
32
Triple Peff
Ta=25°C
VIN=-2.0V
50
40
28
IOUT=
2mA
90 I =
OUT
5mA
80
IOUT=10mA
70
36
70
Peff(%)
70 Ta=25°C
VIN=-5.0V
60
20
Triple IIN
Double IIN
0 1 2
3 4
5
6 7
8
1
2
3
6
7
IOUT=30mA
50
16
40
12
30
8
20
4
10
VIN=-5.0V
0
103
0
9 10
104
IOUT(mA)
105
106
fOSC(Hz)
Fig.9 Power Conversion Efficiency
(Peff)vs. Oscillation Frequency
(fOSC)
Fig.8 Power Conversion Efficiency
(Peff)/Input Current(IIN)vs.
Output Current(IOUT)
Fig.7 Power Conversion Efficiency
(Peff)/Input Current(IIN)vs.
Output Current(IOUT)
4
5
VIN(V)
100
40
Double Peff
Ta=25°C
Fig.6 Output Inpedance(ROUT)vs.
Input Voltage(VIN)
Peff(%)
40
IIN(mA)
20
30
IOUT(mA)
IIN(mA)
Peff(%)
10
Double
100
IOUT(mA)
-15
0
Triple
200
-4
Double
-10
Ta=25°C
VIN=-5V
-1
ROUT(Ω)
VOUT(V)
0
-5
100
IOUT=
0.5mA
IOUT=
80 1mA
IOUT=
2mA
70
-8.000
-7.950
60
VOUT=-15V
Ta=25°C
-2.950
IOUT=4mA
40
-7.900
30
VOUT=-6V
Ta=25°C
Vreg(V)
50
-3.000
Vreg(V)
Peff(%)
90
-2.900
VIN=-1.5V
20
10
0 3
10
104
105
106
fOSC(Hz)
Fig.10 Power Conversion Efficiency(Peff)
vs.Oscillation Frequency(fOSC)
4
-7.850
10-4
10-3
10-2
IOUT(A)
Fig.11 Output Voltage(Vreg)vs. Output
Current(IOUT)
10-1
-2.850
10-4
10-3
10-2
IOUT(A)
Fig.12 Output Voltage(Vreg)vs. Output
Current(IOUT)
10-1
SCI7661COA/MOA
×100(%)
0.30
0.25
VOUT=
-10V
0.15
0.10
VOUT=
-15V
0.05
0.00
0
5
10
IOUT(mA)
15
| Vreg(25°C) |
50
Vreg(Ta) | - | Vreg(25°C) |
Vreg-VOUT
(V)
VOUT=
-5V
0.20
0
-50
-50
CT:
-0.1%/°C
CT:
-0.4%/°C
0
50
100
Ta(°C)
CT:
-0.6%/°C
20
Fig:13 Regulated Output Saturation
Resistance(RSAT)Vreg—VOUT —IOUT
Fig:14 Output Voltage(vreg)vs.
Temperature(Ta)
■ CIRCUIT DESCRIPTION
● C-R Oscillator
The SCI7661C/M contains a C-R oscillator for internal
oscillation. It consists of an external resistor R OSC
connected between the OSC1 pin and OSC2 pin.
Osc1
Osc1
External Clock
ROSC
Osc2
Open
Osc2
C-R Oscillation
External Clock Operation
● Voltage Converters
The voltage converters doubleÅ^triple the input supply voltage (VIN) using clocks generated by the C-R oscillator
VDD=0V
VCC
(+5V)
VDD=0V
GND
VIN=-5V
VIN=-5V
(-5V)
CAP2=2VIN=-10V
VOUT=3VIN=-15V
Typical Doubled Voltage Relations
Typical Tripled Voltage Relations
●Reference Voltage Generator and Voltage Regulator
The reference voltage generator produces reference
voltage needed for operation of regulator circuit. The
voltage regulator is used to regulate a boosted output
voltage and its circuit contains a power-off function which
uses signals from the system for on-off control of the
Vreg output.
VDD
Control signal
Poff
RV
RRV = 100kΩ to 1MΩ
Vreg
Voltage Regulator
● Temperature Gradient Selector Circut
The SCI7661C/M provides the Vreg output with a temperature gradient suitable for LCD driving.
5
SCI7661COA/MOA
● Temperature Gradient Assignment
Vreg Output
Temp. Gradient
CR oscillation
TC1
TC2
Poff
ON
-0.4%/°C
ON
1(VDD)
L(VOUT)
L(VOUT)
ON
-0.1%/°C
ON
1
L
H(VDD)
ON
-0.6%/°C
ON
1
H(VDD)
L
ON
-0.6%/°C
OFF
1
H
H
OFF(Hi-Z)
OFF
0(VIN)
L
L
OFF(Hi-Z)
OFF
H
L
0
OFF(Hi-Z)
OFF
L
H
0
OFF(Hi-Z)
ON
H
H
0
NOTE: The potential at Low level is different between the Poff pin and the TC1/TC2 pin.
Remarks
Cascade connection
Without regulation
■ BASIC EXTERNAL CONNECTION
● Voltage Tripler+Regulator
Vreg output is given a temperature gradient, after
boosted output VOUT regulated. In this connection,
both VOUT and Vreg can be taken out at the same
time.
● Voltage Doubler and Tripler
A doubled voltage can be obtained at VOUT(CAP2-)
by disconnecting capacitor C 2 from the tripler
configuration and shorting CAP2-- (pin4) and VOUT
(pin 8).
5V
C1
10µF
+
C2
10µF
+
−
−
VIN=-5V
1
2
3
14
13
12
4
5
6
7
11
10
9
8
+
C1
10µF
C2
10µF
ROSC 1MΩ
5V
+
1
2
3
4
5
6
7
−
+
−
+
VIN=-5V
VOUT=-15V
–
14 R
OSC
R1 RRV+ C4
13
− 10µF
12
R2
1MΩ
100kΩ
11
~1MΩ
10
Shield wire
9
Vreg=-8V=
8
VOUT=-15V
RRV
−
R VRV
1
C3 10µF
C3 10µF
Tripler+Regulator
(-0.4%/°C selected as temperature gradient)
Voltage Tripler
● Parallel Connection
Parallel connection of n circuits can reduce ROUT to about
1/n, that output impedance R OUT can be reduced by
connecting serial configuraiton. A single smoothing
capacitor C3 can be used commonly for all parallely
connected circuit.
In parallely connection, a regulated output can be
obtained by applying the regulation circuit to only one of
the n parallely connected circuit.
5V
C1 +
10µF −
+
C2 −
10µF
1
2
3
4
5
6
7
C1
10µF
C2
10µF
14
13 ROSC
12
1MΩ
11
10
9
8
+
−
+
−
VIN=-5V
+
−
1
2
3
4
5
6
7
14
C4
+
13 ROSC
10µF
−
12
RRV
1MΩ
11
100kΩ
10
~1MΩ
9
8
Vreg=-10V
VOUT=-15V
C3 10µF
Parallel Connection
● Cascade Connection
Cascade connection of SCI7661C/M (by connecting VIN and VOUT of one stage to VDD and VIN respectively of
the next stage) further increase the output voltage. Note, however, that the serial connection increases the
output impedance.
V'DD=VIN=-15V
+
−
5V
1
2
3
14
13
12
4
5
11
10
6
7
VIN=-5V
10µF
+
−
10µF
+
−
1MΩ
10µF
+
−
9 VOUT=-10V
=VIN'
8
+
−
1
2
3
14
13
12
4
5
11
10
6
9
7
8
+
10µF
−
100kΩ
~
10µF
1MΩ
V'reg=-15V
V'OUT=-20V
10µF
Serial Connection
6
SCI7661COA/MOA
● Positive Voltage Conversion
The input voltage can be doubled or tripled toward the positive
side. (In the doubler configuration, capacitor C2 and diode D3
are disconnected and the diode D3 shorted at the both ends.)
In this case, however, the output voltage decrease by VF(forward
voltage)
For example VDD=0V, VIN=–5V and VF=0.6V, then VOUT=10V–
3×0.6V=8.2 V (if doubled, 5V–2×0.6V=3.8V)
VDD=0V
C1 10µF
+ −
D1
D2
C2 10µF
+ −
5V
D3
VOUT=8.2V
C3 10µF
+ −
1
14
2
13
3
12
4
11
5
10
6
9
8
7
ROSC
1MΩ
VIN=
-5V
Positive Voltage Conversion D1, D2, D3,: Shottky
diodes with small VF are recommended.
● Negative Voltage Conversion + Positive
VDD=0V
+
Voltage Conversion
−
10µF
+
This circuit produces outputs of –15V and +8.2V from
the –5V input. Note that this configuration causes
higher output impedance than in a single function
(negative or positive voltage converter).
VOUT2=13.2V
10µF
−
10µF
5V
VOUT2=
8.2V
10µF
+
+
−
−
+
−
1
2
3
4
5
6
7
14
VDD=5V
13
1MΩ
12
VDD=0V
11
10
9 VOUT1=-15V
8
+
VIN=
-5V
VOUT1=-10V
−
10µF
Negative Voltage Convertion +Positive Voltage Conversion
● Changing the Temperature Gradient through Use of External
Temperature Sensor (Thermistor)
The SCI7661C/M has a temperature gradient selector circuit in its
regulator. It selects any one of the three gradients: –0.1% / °C, –0.4% /
°C and –0.6% / °C. It is necessary that the temperature gradient can be
changed to any other value by connecting a thermistor in series to the
output voltage control resistor RRV.
1
14
2
13
4
12 +
−
11
5
10
6
9
7
8
3
VDD
R1
10µF
RRV
RT
RP
Vreg
Example of Change of Temperature Gradient
■ PACKAGE DIMENSIONS
19.7max
Plastic DIP-14pin
(0.775max)
19±0.1
(0.748±0.003)
8
6.3±0.1
(0.248±0.003)
14
1
7
1.5
0.8±0.1
+0.004
(0.031 –0.003 )
3min
4.4±0.1
+0.004
(0.119min) (0.173 –0.003 )
(0.059)
+0.03
.01
0.25 –0
+0.001
2.54
(0.1)
±0.1
0.46+0.004
(0.018 –0.003 )
0°
15°
7.62
(0.3)
(0.01 –0
)
Unit: mm
(inch)
7
SCI7661COA/MOA
Plastic SOP5-14pin
10.5max
(0.413max)
±0.2
10.2+0.007
(0.402 –0.008 )
7
0.4±0.1
+0.003
(0.016 –0.004 )
0.1±0.08
1.27±0.1
(0.05±0.003)
(0.004±0.003)
2.3
(0.09)
2.2max
1
8±0.3
INDEX
(0.315±0.011)
5.5±0.2
+0.007
(0.217 –0.008 )
8
(0.086max)
14
±0.1
0.15+0.003
(0.006 –0.004)
0.4
(0.016)
1.25
(0.049)
Unit: mm
(inch)
8
SCI7661COA/MOA
NOTICE
No part of this material may be reproduced or duplicated in any form or by any means without the written permission of Seiko
Epson. Seiko Epson reserves the right to make changes to this material without notice. Seiko Epson does not assume any liability
of any kind arising out of any inaccuracies contained in this material or due to its application or use in any product or circuit and,
further, there is no representation that this material is applicable to products requiring high level reliability, such as, medical
products. Moreover, no license to any intellectual property rights is granted by implication or otherwise, and there is no
representation or warranty that anything made in accordance with this material will be free from any patent or copyright
infringement of a third party. This material or portions thereof may contain technology or the subject relating to strategic products
under the control of the Foreign Exchange and Foreign Trade Control Law of Japan and may require an export license from the
Ministry of International Trade and Industry or other approval from another government agency.
All product names mentioned herein are trademarks and/or registered trademarks of their respective companies.
©Seiko Epson Corporation 1998 All rights reserved.
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Phone: +81-(0)42-587-5816
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Phone: +81-(0)42-587-5812
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Phone: +81-(0)42-587-5814
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Electric Device Information of EPSON WWW server
http://www.epson.co.jp
9