Datasheet

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General Description

The MAX5075 is a +4.5V to +15V push-pull, current-fed

topology driver subsystem with an integrated oscillator

for use in telecom module power supplies. The device

drives two MOSFETs connected to a center-tapped

transformer primary providing secondary-side, isolated,

negative or positive voltages. This device features a pro-

grammable, accurate, integrated oscillator with a syn-

chronizing clock output that synchronizes an external

PWM regulator. A single external resistor programs the

internal oscillator frequency from 50kHz to 1.5MHz.

The MAX5075 incorporates a dual MOSFET driver with

±3A peak drive currents and 50% duty cycle. The

MOSFET driver generates complementary signals to

drive external ground-referenced n-channel MOSFETs.

The MAX5075 is available with a clock output frequency

to MOSFET driver frequency ratio of 1x, 2x, and 4x. The

MAX5075 is available in a thermally enhanced 8-pin

µMAX

package and is specified over the -40°C to

+125°C operating temperature range.

Applications

Current-Fed, High-Efficiency Power-Supply Modules

Power-Supply Building Subsystems

Push-Pull Driver Subsystems

Features

♦ Current-Fed, Push-Pull Driver Subsystem

♦ Programmable, Accurate Internal Oscillator

♦ Single +4.5V to +15V Supply Voltage Range

♦ Dual ±3A Gate-Drive Outputs

♦ 1mA Operating Current at 250kHz with No

Capacitive Load

♦ Synchronizing Clock Frequency Generation

Options

♦ Thermally Enhanced 8-Pin µMAX Package

♦ -40°C to +125°C Operating Temperature Range

MAX5075

Push-Pull FET Driver with Integrated Oscillator

and Clock Output

________________________________________________________________ Maxim Integrated Products 1

Ordering Information

19-3662; Rev 1; 5/07

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at

1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

Pin Configuration appears at end of data sheet.

PART

PIN-

PACKAGE

TOP

MARK

PKG

CODE

CLK

NDRV_

RATIO

MAX5075AAUA

8 µMAX-EP* AAAU U8E-2

MAX5075BAUA

8 µMAX-EP* AAAV U8E-2

MAX5075CAUA

8 µMAX-EP* AAAW U8E-2

*EP = Exposed paddle.

Note: All devices specified for -40°C to +125°C operating

temperature range.

MAX5075

1nF

4.7kΩ

NDRV2

DRVH

DRVL

GND

PWM

CONTROLLER

SYNCIN

NDRV1

PGNDI.C.

CLK

OUT

Typical Operating Circuit

µMAX is a registered trademark of Maxim Integrated Products, Inc.

Summary of content (8 pages)

PAGE 1
9-3662; Rev 1; 5/07 Push-Pull FET Driver with Integrated Oscillator and Clock Output Features The MAX5075 is a +4.5V to +15V push-pull, current-fed topology driver subsystem with an integrated oscillator for use in telecom module power supplies. The device drives two MOSFETs connected to a center-tapped transformer primary providing secondary-side, isolated, negative or positive voltages.
PAGE 2
MAX5075 Push-Pull FET Driver with Integrated Oscillator and Clock Output ABSOLUTE MAXIMUM RATINGS VCC to DGND, PGND .............................................-0.3V to +18V CLK, RT to DGND.....................................................-0.3V to +6V NDRV1, NDRV2 to PGND...........................-0.3V to (VCC + 0.3V) DGND to PGND.....................................................-0.3V to +0.3V CLK Current......................................................................
PAGE 3
Push-Pull FET Driver with Integrated Oscillator and Clock Output SUPPLY CURRENT vs. CCLK 3 fOSC = 250kHz fOSC = 100kHz 2 fOSC = 50kHz 1 0 1.35 1.30 1.25 1.20 1.15 7 8 1.10 1.08 1.06 1.04 1.02 9 10 11 12 13 14 15 MAX5075 toc03 1.12 1.05 1.00 0 20 40 60 100 80 -50 -25 0 25 50 75 SUPPLY VOLTAGE (V) CCLK (pF) TEMPERATURE (°C) CLK RISE TIME vs. SUPPLY VOLTAGE CLK RISE TIME vs. TEMPERATURE CLK FALL TIME vs. SUPPLY VOLTAGE CCLK = 30pF 45 39.5 MAX5075 toc04 50 40 39.
PAGE 4
Typical Operating Characteristics (continued) (VCC = +12V, RRT = 124kΩ, NDRV_ = open, CLK = open.) NDRV FREQUENCY vs. CLK FREQUENCY OSCILLATOR FREQUENCY vs.
PAGE 5
Push-Pull FET Driver with Integrated Oscillator and Clock Output PIN NAME FUNCTION 1 CLK Synchronizing Clock Output. Clock output with a ±10mA peak current drive that can be used to synchronize an external PWM regulator. CLK/NDRV1 frequency has a 1x, 2x, or 4x ratio. See the Synchronizing Clock Output section. 2 I.C. Internal Connection. Connect to ground. Internal function. 3 RT Oscillator Timing Resistor Connection. Bypass RT with a series combination of a 4.
PAGE 6
MAX5075 Push-Pull FET Driver with Integrated Oscillator and Clock Output Detailed Description The MAX5075 is a +4.5V to +15V push-pull, current-fed topology driver subsystem with an integrated oscillator for use in 48V module power supplies. The MAX5075 features a programmable, accurate integrated oscillator with a synchronizing clock output that can be used to synchronize an external PWM stage. A single external resistor programs the internal oscillator frequency from 50kHz to 1.5MHz.
PAGE 7
Push-Pull FET Driver with Integrated Oscillator and Clock Output • Two AC current loops form between the device and the gate of the driven MOSFETs. The MOSFETs look like a large capacitance from gate to source when the gate pulls low. The current loop is from the MOSFET gate to NDRV1 and NDRV2 of the MAX5075, to PGND, and to the source of the MOSFET.
PAGE 8
Package Information (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to www.maxim-ic.com/packages.) 8L, µMAX, EXP PAD.EPS MAX5075 Push-Pull FET Driver with Integrated Oscillator and Clock Output 21-0107 C 1 1 Revision History Pages changed at Rev 1: 1, 2, 5, 6, 8 Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product.