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N = Number of Track pins connected together

10 kΩ

V

Vo

R

SET1

C

O1

+

C

+

PTH12050W

5

6

3

4

2

Track

V

I

V

O

GND

Inhibit

1

Adjust

TL7712A

V

CC

GND

SENSE

RESIN

REF

CT

RESET

RESET

8

7

2

1

3

5

6

4

C

T

C

REF

R

RST

Vo

C

O2

+

C

+

PTH12060W

7

10

4

5

6

2

3

98

Track

V

I

V

O

GND

Inhibit

1

Up Dn

Sense

Adjust

SET2

U1

U2

U3

R

2.0 kΩ

11.5 kΩ

I2

0.1 µF

3.3 µF

50 Ω

I1

R

PTH12010W, PTH12010L

SLTS205E–JUNE 2003–REVISED APRIL 2006

Auto-Track slew rate. If the Track pin is pulled low at a slew rate greater than 1 V/ms, the discharge of the

output capacitors will induce large currents which could exceed the peak current rating of the module. This will

result in a reduction in the maximum allowable output capacitance as listed in the Electrical Characteristics

table. When controlling the Track pin of the PTH12010W using a voltage supervisor IC, the slew rate is

Notes on Use of Auto-Track™

1. The Track pin voltage must be allowed to rise above the module set-point voltage before the module

regulates at its adjusted set-point voltage.

2. The Auto-Track function tracks almost any voltage ramp during power up, and is compatible with ramp

speeds of up to 1 V/ms.

4. The module cannot follow a voltage at its Track control input until it has completed its soft-start initialization.

This takes about 40 ms from the time that a valid voltage has been applied to its input. During this period, it

is recommended that the Track pin be held at ground potential.

is disabled, the output voltage rises at a quicker and more linear rate after input power has been applied.

Figure 16. Sequenced Power Up and Power Down Using Auto-Track

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