CMOS Switched-Capacitor
Voltage Converters
ADM660/ADM8660
FEATURES
ADM660: Inverts or Doubles Input Supply Voltage
ADM8660: Inverts Input Supply Voltage
100 mA Output Current
Shutdown Function (ADM8660)
2.2 F or 10 F Capacitors
0.3 V Drop at 30 mA Load
+1.5 V to +7 V Supply
Low Power CMOS: 600 A Quiescent Current
Selectable Charge Pump Frequency (25 kHz/120 kHz)
Pin Compatible Upgrade for MAX660, MAX665, ICL7660
Available in 16-Lead TSSOP Package
APPLICATIONS
Handheld Instruments
Portable Computers
Remote Data Acquisition
Op Amp Power Supplies
GENERAL DESCRIPTION
TYPICAL CIRCUIT CONFIGURATIONS
+1.5V TO +7V
INPUT
FC
V+
ADM660
OSC
LV
OUT
C2
INVERTED
NEGATIVE
OUTPUT
CAP+
C1
+
10 F
GND
CAP–
+
10 F
Voltage Inverter Configuration (ADM660)
+1.5V TO +7V
INPUT
FC
C1
+
10 F
SHUTDOWN
CONTROL
ADM8660
V+
CAP+
GND
CAP–
SD
LV
OUT
C2
INVERTED
NEGATIVE
OUTPUT
The ADM660/ADM8660 is a charge-pump voltage converter
that can be used to either invert the input supply voltage giving
V
OUT
= –V
IN
or double it (ADM660 only) giving V
OUT
= 2 V
IN
.
Input voltages ranging from +1.5 V to +7 V can be inverted into
a negative –1.5 V to –7 V output supply. This inverting scheme
is ideal for generating a negative rail in single power supply
systems. Only two small external capacitors are needed for the
charge pump. Output currents up to 50 mA with greater than
90% efficiency are achievable, while 100 mA achieves greater
than 80% efficiency.
A Frequency Control (FC) input pin is used to select either
25 kHz or 120 kHz charge-pump operation. This is used to
optimize capacitor size and quiescent current. With 25 kHz
selected, a 10
µF
external capacitor is suitable, while with 120 kHz
the capacitor may be reduced to 2.2
µF.
The oscillator frequency
on the ADM660 can also be controlled with an external capacitor
connected to the OSC input or by driving this input with an
external clock. In applications where a higher supply voltage is
desired it is possible to use the ADM660 to double the input
voltage. With input voltages from 2.5 V to 7 V, output voltages
from 5 V to 14 V are achievable with up to 100 mA output current.
The ADM8660 features a low power shutdown (SD) pin instead
of the external oscillator (OSC) pin. This can be used to disable
the device and reduce the quiescent current to 300 nA.
+
10 F
Voltage Inverter Configuration with Shutdown (ADM8660)
The ADM660 is a pin compatible upgrade for the MAX660,
MAX665, ICL7660, and LTC1046.
The ADM660/ADM8660 is available in 8-lead DIP and
narrow-body SOIC. The ADM660 is also available in a 16-lead
TSSOP package.
ADM660/ADM8660 Options
Option
Inverting Mode
Doubling Mode
External Oscillator
Shutdown
Package Options
R-8
N-8
RU-16
ADM660
Y
Y
Y
N
Y
Y
Y
ADM8660
Y
N
N
Y
Y
Y
N
REV.
C
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties that
may result from its use. No license is granted by implication or otherwise
under any patent or patent rights of Analog Devices. Trademarks and
registered trademarks are the property of their respective companies.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700
www.analog.com
Fax:
781/461-3113
©
2011
Analog Devices, Inc. All rights reserved.
ADM660/ADM8660–SPECIFICATIONS
Parameter
Input Voltage, V+
3.5
1.5
2.5
Supply Current
0.6
2.5
Output Current
Output Resistance (ADM660)
Output Resistance (ADM8660)
Output Resistance (ADM8660)
Charge-Pump Frequency
OSC Input Current
Power Efficiency (FC = Open) (ADM660)
Power Efficiency (FC = Open) (ADM8660)
Power Efficiency (FC = Open) (ADM8660)
Power Efficiency (FC = Open) (ADM660)
Power Efficiency (FC = Open) (ADM8660)
Power Efficiency (FC = Open) (ADM8660)
Power Efficiency (FC = Open)
Voltage Conversion Efficiency
Shutdown Supply Current, I
SHDN
Shutdown Input Voltage, V
SHDN
Shutdown Exit Time
*C1
and C2 are low ESR (<0.2
W)
electrolytic capacitors.
High ESR degrade performance.
Specifications subject to change without notice.
(V+ = +5 V, C1, C2 = 10 F,* T
A
= T
MIN
to T
MAX
, unless
otherwise noted.)
Unit
V
V
V
mA
mA
mA
W
W
W
kHz
kHz
mA
mA
%
%
%
Test Conditions/Comments
R
L
= 1 kW
Inverting Mode, LV = Open
Inverting Mode, LV = GND
Doubling Mode, LV = OUT
No Load
FC = Open (ADM660), GND (ADM8660)
FC = V+, LV = Open
I
L
= 100 mA
I
L
= 100 mA, T
A
= 25∞C
I
L
= 100 mA, T
A
= –40∞C to +85∞C
FC = Open (ADM660), GND (ADM8660)
FC = V+
FC = Open (ADM660), GND (ADM8660)
FC = V+
R
L
= 1 kW Connected from V+ to OUT
R
L
= 1 kW Connected from V+ to OUT,
T
A
= +25∞C
R
L
= 1 kW Connected from V+ to OUT,
T
A
= –40∞C to +85∞C
R
L
= 500
W
Connected from OUT to GND
R
L
= 500
W
Connected from OUT to GND,
T
A
= +25∞C
R
L
= 500
W
Connected from OUT to GND,
T
A
= –40∞C to +85∞C
I
L
= 100 mA to GND
No Load
ADM8660, SHDN = V+
SHDN High = Disabled
SHDN Low = Enabled
I
L
= 100 mA
Min
Typ
Max
7.0
7.0
7.0
1
4.5
15
15
16.5
100
9
9
25
120
±
5
±
25
90
90
88.5
90
90
88.5
81.5
99
2.4
0.8
500
99.96
0.3
5
93
93
94
94
%
%
%
%
%
mA
V
V
ms
–2–
REV.
C
ADM660/ADM8660
ABSOLUTE MAXIMUM RATINGS*
(T
A
= +25°C, unless otherwise noted.)
Input Voltage (V+ to GND, GND to OUT) . . . . . . . . +7.5 V
LV Input Voltage . . . . . . . . . . (OUT – 0.3 V) to (V+, +0.3 V)
FC and OSC Input Voltage
. . . . . . . . . . . (OUT – 0.3 V) or (V+, –6 V) to (V+, +0.3 V)
OUT, V+ Output Current (Continuous) . . . . . . . . . . . 120 mA
Output Short Circuit Duration to GND . . . . . . . . . . . 10 secs
Power Dissipation, N-8 . . . . . . . . . . . . . . . . . . . . . . . 625 mW
(Derate 8.3 mW/°C above +50°C)
θ
JA
, Thermal Impedance . . . . . . . . . . . . . . . . . . . . 120°C/W
Power Dissipation, R-8 . . . . . . . . . . . . . . . . . . . . . . . 450 mW
(Derate 6 mW/°C above +50°C)
θ
JA
, Thermal Impedance . . . . . . . . . . . . . . . . . . . . 170°C/W
Power Dissipation, RU-16 . . . . . . . . . . . . . . . . . . . . . 500 mW
(Derate 6 mW/°C above +50°C)
θ
JA
, Thermal Impedance . . . . . . . . . . . . . . . . . . . . 158°C/W
Operating Temperature Range
Industrial (A Version) . . . . . . . . . . . . . . . . – 40°C to +85°C
Storage Temperature Range . . . . . . . . . . . –65°C to +150°C
Lead Temperature Range (Soldering 10 sec) . . . . . . . . +300°C
Vapor Phase (60 sec) . . . . . . . . . . . . . . . . . . . . . . . . +215°C
Infrared (15 sec) . . . . . . . . . . . . . . . . . . . . . . . . . . . . +220°C
ESD Rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . >2000 V
*This
is a stress rating only; functional operation of the device at these or any other
conditions above those indicated in the operation section of this specification is not
implied. Exposure to absolute maximum rating conditions for extended periods
may affect device reliability.
CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily
accumulate on the human body and test equipment and can discharge without detection. Although the
ADM660/ADM8660 features proprietary ESD protection circuitry, permanent damage may occur on
devices subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are
recommended to avoid performance degradation or loss of functionality.
REV.
C
–3–
ADM660/ADM8660
PIN CONNECTIONS
8-Lead
FC 1
CAP+ 2
8 V+
FC 1
CAP+ 2
8 V+
7 OSC
TOP VIEW
GND 3 (Not to Scale) 6 LV
5 OUT
ADM660
7 SD
TOP VIEW
GND 3 (Not to Scale) 6 LV
5 OUT
ADM8660
CAP– 4
CAP– 4
16-Lead
NC 1
NC 2
FC 3
CAP+ 4
16 NC
15 NC
ADM660
14 V+
TOP VIEW 13 OSC
(Not to Scale)
12 LV
GND 5
11 OUT
10 NC
9 NC
CAP– 6
NC 7
NC 8
NC = NO CONNECT
PIN FUNCTION DESCRIPTIONS
Inverter Configuration
Doubler Configuration (ADM660 Only)
Mnemonic
FC
Function
Frequency Control Input for Internal Oscillator
and Charge Pump. With FC = Open (ADM660)
or connected to GND (ADM8660), f
CP
= 25 kHz;
with FC = V+, f
CP
= 120 kHz.
Positive Charge-Pump Capacitor Terminal.
Power Supply Ground.
Negative Charge-Pump Capacitor Terminal.
Output, Negative Voltage.
Low Voltage Operation Input. Connect to GND
when input voltage is less than 3.5 V. Above
3.5 V, LV may be connected to GND or left
unconnected.
ADM660: Oscillator Control Input. OSC is
connected to an internal 15 pF capacitor. An
external capacitor may be connected to slow the
oscillator. An external oscillator may also be
used to overdrive OSC. The charge-pump
frequency is equal to 1/2 the oscillator frequency.
ADM8660: Shutdown Control Input. This in-
put, when high, is used to disable the charge
pump thereby reducing the power consumption.
Positive Power Supply Input.
Mnemonic
FC
Function
Frequency Control Input for Internal Oscillator
and Charge Pump. With FC = Open, f
CP
=
25 kHz; with FC = V+, f
CP
= 120 kHz.
Positive Charge-Pump Capacitor Terminal.
Positive Input Supply.
Negative Charge-Pump Capacitor Terminal.
Ground.
Low Voltage Operation Input. Connect to OUT.
Must be left unconnected in this mode.
Doubled Positive Output.
CAP+
GND
CAP–
OUT
LV
OSC
V+
CAP+
GND
CAP–
OUT
LV
OSC
SD
V+
–4–
REV.
C
Typical Performance Characteristics–ADM660/ADM8660
3.0
100
I
L
= 10mA
90
2.5
SUPPLY CURRENT – mA
POWER EFFICIENCY – %
VOLTAGE DOUBLER
LV = OUT
2.0
80
70
60
50
I
L
= 1mA
1.5
I
L
= 50mA
1.0
LV = GND
0.5
LV = OPEN
0
1.5
I
L
= 80mA
40
30
3.5 7
5.5
SUPPLY VOLTAGE – Volts
.5
1k
10k
100k
CHARGE-PUMP FREQUENCY – Hz
1M
TPC 1. Power Supply Current vs. Voltage
TPC 4. Efficiency vs. Charge-Pump Frequency
–3.0
EFFICIENCY
–3.4
OUTPUT VOLTAGE – Volts
100
3.5
3.0
80
SUPPLY CURRENT – mA
2.5
2.0
LV = GND
VOLTAGE DOUBLER
1.5
1.0
0.5
–3.8
60
–4.2
V
OUT
–4.6
40
20
LV = GND
VOLTAGE INVERTER
1
100
10
CHARGE-PUMP FREQUENCY – kHz
1000
EFFICIENCY – %
–5.0
0
20
40
60
LOAD CURRENT – mA
80
0
100
0
TPC 2. Output Voltage and Efficiency vs. Load Current
TPC 5. Power Supply Current vs. Charge-Pump
Frequency
120
V+ = +6.5V
V+ = +5.5V
V+ = +4.5V
1.6
OUTPUT VOLTAGE DROP
FROM SUPPLY VOLTAGE – Volts
100
1.2
V+ = +3.5V
EFFICIENCY – %
80
V+ = +3.5V
60
V+ = +1.5V
40
V+ = +2.5V
V+ = +2.5V
0.8
V+ = +1.5V
V+ = +5.5V
0.4
V+ = +4.5V
20
0
0
20
40
60
LOAD CURRENT – mA
80
100
0
0
20
40
60
LOAD CURRENT – mA
80
100
TPC 3. Output Voltage Drop vs. Load Current
TPC 6. Power Efficiency vs. Load Current
REV.
C
–5–
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