4-8

TELCOM SEMICONDUCTOR, INC.

TC660

100mA CHARGE PUMP DC-TO-DC

VOLTAGE CONVERTER

TYPICAL CHARACTERISTICS (Cont.)

Oscillator Frequency

vs. External Capacitance

13)

11)

12)

Oscillator Frequency

vs. Temperature

Oscillator Frequency

vs. Temperature

TEMPERATURE (

°C)

TEMPERATURE (

°C)

100

80

60

40

20

0

-40

20

40

-20

0

100

60

80

CAPACITANCE (pF)

100

10

1

0.1

0.01

12

5

20

10

10000

2000

100

500

FC = V+

FC = OPEN

Oscillator Frequency

vs. Supply Voltage

10)

SUPPLY VOLTAGE (V)

100

80

60

40

20

0

1.0

2.0

1.5

2.5 3.0 3.5 4.0 4.5 5.0 5.5

LV GROUNDED

FC = V+, OSC = OPEN

LV OPEN

FC = V+, OSC = OPEN

TC7660 and TC660 Output

Voltage and Power Efficiency

14)

LOAD CURRENT (mA)

-3.0

-3.4

-3.8

-4.2

-4.6

-5.0

0

2.0

60

40

100

80

100

92

84

76

68

60

TC660

TC7660

EFF

VOUT

TC7660

TC660

12

10

8

6

4

2

0

0

20

40

-20

-40

80

60

100

FC= OPEN, OSC = OPEN

PIN DESCRIPTION

Pin No.

Symbol

Description

1

FC

Internal Oscillator frequency control. f

≈ 10 kHz when FC ≈ OPEN; ≈ 90 kHz when

2

External capacitor, + terminal

3

GND

Power-Supply Ground (Inverter) or Positive Input (Doubler)

4

External capacitor, – terminal

Negative Voltage output (Inverter) or Ground (Doubler)

6

LV

open or GND above 3V. When overdriving OSC, connect to GND.

7

OSC

For external control of internal OSC. Connect ext. C from OSC to GND (close to pkg.)

to reduce frequency of oscillator

Positive Voltage Input (Inverter) or Output (Doubler)