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PT6935 Series

11-A 5V/3.3V-Input Dual Output

Integrated Switching Regulator

Power-up Sequencing

The PT6935 series of regulators provide two output voltages,

offered by the PT6935 series provides power for both a low-

voltage processor core, and the associated digital support

circuitry. In addition, each output is internally sequenced

during power-up and power-down to comply with the

requirements of most DSP and µP IC’s, and their accompa-

nying chipsets. Figure 1 shows the typical waveforms of the

input power is applied or the module is enabled via the

Standby pin. Following a delay of about 10 to 15 milli-secs,

voltages have reached full voltage.

The output voltages from the PT6935 series regulators are

by a highly efficient switching regulator. The lower output

The load specifications for each model of the PT6935

series gives both a ‘Typical’ (Typ) and ‘Maximum’ (Max)

load current for each output. For operation within the

comply with the following limits:-

other value than the default output voltage, the absolute

with the following equation.

=

2.5

Adc

Consult the specification table for each model of the series

for the actual numeric values.

Figure 1; PT6935 Series Power-up

V1 (1V/Div)

V2 (1V/Div)

Vstby

(10V/Div)

HORIZ SCALE: 5ms/Div

PT6935 Series

Characteristic

Symbol

Conditions

Min

Typ

Max

Units

Short Circuit Current

—

17

—

A

Switching Frequency

300

350

400

kHz

Standby (Pin 3)

Referenced to GND (pin 7)

Input High Voltage

—

—

V

Input Low Voltage

–0.1

—

+0.4

Input Low Current

—

-0.5

–

mA

Standby Input Current

pin 3 to GND

—

7

25

mA

External Output Capacitance

—

µF

0

—

330

MaximumOperating

—

°C

TemperatureRange

Storage Temperature

—

–40

—

+125

°C

Mechanical Shock

Per Mil-STD-883D, Method 2002.3

1msec,½Sine,mounted

—

500

—

G’s

Mechanical Vibration

Per Mil-STD-883D, Method 2007.2

—

—G’s

20-2000 Hz, Soldered in a PC board

Weight

—

Vertical/Horizontal

—

26

—

grams

Flammability

—

MeetsUL94V-O

Notes:

(1) The Standby (pin 3) has an internal pull-up, and if it is left open circuit the module will operate when input power is applied. The open-circuit voltage is less

than 15V. Refer to the application notes for interface considerations.

(2) A value of 300µF is sufficient if Oscon® or low ESR tantalum type capacitors are used. The total combined ESR of all output capacitance at 100kHz must

be (greater than) >12 m

Ω, and (less or equal to) ≤150mΩ.

(3) For operating temperatures below 0°C, Cin and Cout must have stable characteristics. Use either tantalum or Oscon® capacitors.

(4) See Safe Operating Area curves for the specific output voltage combination, or contact the factory for the appropriate derating.

(5) Only the case pins on through-hole pin configurations (N & A) must be soldered. For more information see the applicable package outline drawing.

Input/Output Capacitors: The PT6935 series requires a 330µF electrolytic capacitor at both the input and output for proper operation (300µF for Oscon® or low ESR

tantalum). In addition, the input capacitance must be rated for a minimum of 1.0Arms ripple current. For transient or dynamic load applications, additional capacitance

may be required. Refer to the application notes for more information.

Not Recommended For New Designs