4-5
TELCOM SEMICONDUCTOR, INC.
7
6
5
4
3
1
2
8
TC660
100mA CHARGE PUMP DC-TO-DC VOLTAGE CONVERTER
FEATURES
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Pin Compatible with TC7660
High Output Current ..................................... 100mA
Converts (+1.5V to 5.5V) to (– 1.5V to – 5.5V)
Power Efficiency @100mA......................... 88% typ
Low Power Consumption ................200
μ
A @ 5 V
IN
Low Cost and Easy to Use
— Only Two External Capacitors Required
Selectable Oscillator Frequency ....... 10kHz/90kHz
ESD Protection ...................................................4kV
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APPLICATIONS
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Laptop Computers
μ
P Based Controllers
Process Instrumentation
Automotive Instruments
GENERAL DESCRIPTION
The TC660 DC-to-DC voltage converter generates a
negative voltage supply, that can support a 100mA maxi-
mum load, from a positive voltage input of 1.5V to 5.5V. Only
two external capacitors are required.
Power supply voltage is stored on an undedicated
capacitor then inverted and transferred to an output reser-
voir capacitor. The on-board oscillator normally runs at a
frequency of 10kHz with V
+
at 5V. This frequency can be
lowered by the addition of an external capacitor from OSC
(pin 7) to ground, or raised to 90kHz by connecting the
frequency control pin (FC) to V
+
, in order to optimize capaci-
tor size, quiescent current, and output voltage ripple
frequency. Operation using input voltage between 1.5V and
3.0V is accommodated by grounding the LV input (pin 6).
Operation at higher input voltages (3.0V to 5.5V) is accom-
plished by leaving LV open.
The TC660 open circuit output voltage is within 0.1% of
the input voltage with the output open-circuited. Power
conversion efficiency is 98% when output load is between
2mA and 5mA.
1
2
3
4
8
7
6
5
TC660CPA
TC660EPA
FC
CAP+
GND
CAP–
VOUT
LV
OSC
+
V
1
2
3
4
8
7
6
5
TC660COA
TC660EOA
FC
CAP+
GND
CAP–
VOUT
LV
OSC
+
V
TC660
GND
INTERNAL
VOLTAGE
REGULATOR
RC
OSCILLATOR
VOLTAGE–
LEVEL
TRANSLATOR
÷
2
V+CAP+
8
2
7
6
OSC
LV
3
LOGIC
NETWORK
VOUT
5
CAP–
4
1
FC
FUNCTIONAL BLOCK DIAGRAM
PIN CONFIGURATION
(DIP and SOIC)
ORDERING INFORMATION
Part No.
Package
Temp. Range
TC660COA
TC660CPA
TC660EOA
TC660EPA
TC7660EV
8-Pin SOIC
8-Pin Plastic DIP
8-Pin SOIC
8-Pin Plastic DIP
Evaluation Kit for
Charge Pump Family
0
°
C to +70
°
C
0
°
C to +70
°
C
– 40
°
C to +85
°
C
– 40
°
C to +85
°
C
TC660-2 9/10/96
EVALUATION
KIT
AVAILABLE