4-95

TELCOM SEMICONDUCTOR, INC.

7

6

5

4

3

1

2

8

Output Section

—

7

15

—

7

15

Ω

—

11

20

—

11

15

Ω

Rise Time

—

40

60

—

35

60

nsec

Fall Time

—

30

60

—

30

40

nsec

Cross Conduction

In Coulombs (Note 1)

—

6.5

—

—

6.5

—

nC

Note 1

—

—

18

—

—

18

V

Undervoltage Lockout Section

Start Threshold

x8C43

7.9

8.4

8.8

7.9

8.4

8.8

V

Undervoltage Threshold

x8C43

7.2

7.6

7.9

7.2

7.6

7.9

V

PWM Section

Maximum Duty Cycle

x8C43 (Note 1)

95

97

100

95

97

100

%

Minimum Duty Cycle

0

0

%

Supply Current

Start Up

50

170

300

50

170

300

µA

Operating

1

2

1

1.5

mA

TC18C4X

TC28C4X

TC38C4X

Parameter

Test Conditions

Min

Typ

Max

Min

Typ

Max

Units

where 0

4. Output frequency equals oscillator frequency for the

x8C43.

combination.

NOTES: 1. These parameters, although guaranteed over the

recommended operating conditions, are not tested in

production.

2. Parameter measured at trip point of latch.

3. Gain ratio is defined as:

TelCom Semiconductor reserves the right to make changes in the circuitry or specifications detailed in this manual at any time without notice. Minimums

and maximums are guaranteed. All other specifications are intended as guidelines only. TelCom Semiconductor assumes no responsibility for the use of

any circuits described herein and makes no representations that they are free from patent infringement.

*Static-sensitive device. Unused devices must be stored in conductive material. Protect devices from static discharge and static fields. Stresses above

those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only and functional operation of

the device at these or any other conditions above those indicated in the operational sections of the specifications is not implied. Exposure to Absolute

Maximum Rating Conditions for extended periods may affect device reliability.

PIN DESCRIPTION

Pin No.

Pin No

Pin No

8-Pin

14-Pin

16-Pin

Symbol

Description

2

1

NC

No Connection

4

2

NC

No Connection

1

1

3

CMPTR

Compensation of the feedback loop response.

234

Feedback of voltage to error amplifier to regulate voltage.

355

For sensing pass transistor current and terminate drive when current

limit threshold is reached at this pin.

4

7

6

Capacitor and resistor input to set oscillator frequency of this PWM

TC18C43

TC28C43

TC38C43

BiCMOS CURRENT MODE

PWM CONTROLLERS