Diodes PAM2423 User Manual

Description

The PAM242x devices are high-performance, fixed frequency,

current-mode PWM step-up DC/DC converters that incorporate

internal power MOSFETs. The PAM242x includes an integrated

power MOSFET that supports peak currents of up to 3A/4.5A/5.5A.

The PAM242x utilizes simple external loop compensation allowing

optimization between component size, cost and AC performance

across a wide range of applications. Additional functions include an

externally programmable soft-start function for easy inrush current

control, internal over-voltage protection (OVP), cycle-by-cycle current

limit protection, under voltage lock-out and thermal shutdown.

The PAM242x is available in the small SOP-8(EP) package.

Features

 Greater than 90% Efficiency  Adjustable Output Voltage Up to 24V  Internal 24V Power MOSFET  Peak Current 3A,4.5A,5.5A  520kHz Frequency  Built-in Over-Voltage Protection (OVP)  Open Protection  Programmable Soft-Start Function  Thermal Shutdowns  Under-Voltage-Lockout  Over-Current Protection  SOP-8(EP) Package

Typical Applications Circuit

Product Line o

Diodes Incorporated

PAM2421/ PAM2422/ PAM2423

3A, 4.5A, 5.5A PWM STEP-UP DC-DC CONVERTER

Pin Assignments

Applications

 TFT LCD Monitors  Battery-Powered Equipment  Set-Top Boxes  DSL and Cable Modems and Routers

PAM2421/PAM2422/PAM2423

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Pin Descriptions

Number

1 PGND 2 IN

3 EN

4 COMP 5 AGND

6 FB

7 SS

8 SW

— Exposed PAD

SOP-8(EP)

Pin Name

Power Ground

Supply Input

Enable Control. Connect to a logic high level to enable the IC. Connect to a logic low level to disable the IC. When unused, connect EN pin to IN (do not leave pin floating).

Error Amplifier Compensation Node

Analog Ground

Feedback Input.Connect this pin a resistor divider from the output to set the output voltage. FB is regulated to 1.262V.

Soft Start Control Input. Connect a capacitor from this pin to Ground to set soft-start timing duration. SS is discharged to ground in shutdown. SS may be left unconnected if soft start is not desired.

Switch Output. Connect this pin to the inductor and the schottky diode. To minimize EMI, minimize the PCB trace path between this pin and the input bypass capacitor.

Connected to Ground

Functional Block Diagram

Product Line o

Diodes Incorporated

PAM2421/ PAM2422/ PAM2423

Function

PAM2421/PAM2422/PAM2423

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November 2012

Product Line o

Diodes Incorporated

PAM2421/ PAM2422/ PAM2423

Absolute Maximum Ratings (@T

These are stress ratings only and functional operation is not implied. Exposure to absolute maximum ratings for prolonged time periods may affect device reliability. All voltages are with respect to ground.

Parameter Rating Unit

SW to Ground -0.3 to +28 V

VIN, EN, FB, SS, COMP to Ground -0.3 to +6.5 V

Continuous SW Current Internally Limited V

Operating Temperature Range -40 to +150 °C

Storage Temperature Range -55 to +150 °C

Lead Temperature (Soldering, 10 sec) 300 °C

Recommended Operating Conditions (@T

Parameter Rating Unit

Junction Temperature Range -40 to +125

Ambient Temperature Range -40 to +85

= +25°C, unless otherwise specified.)

°C

Thermal Information

Parameter Symbol Package Max Unit

Thermal Resistance (Junction to Case)

Thermal Resistance (Junction to Ambient)

PAM2421/PAM2422/PAM2423

Document number: DSxxxxx Rev. 1 - 1

SOP-8(EP) 75

SOP-8(EP) 180

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°C/W

November 2012

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