MAX1875, MAX1876 Dual 180° Out-of-Phase PWM Step-Down Controllers with POR

Description

The MAX1875/MAX1876 dual, synchronized, step-down controller generates two outputs from input supplies ranging from 4.75V to 23V. Each output is adjustable from sub-1V to 18V and supports loads of 10A or higher. Input voltage ripple and total RMS input ripple current are reduced by synchronized 180° out-of-phase operation.

The switching frequency is adjustable from 100kHz to 600kHz with an external resistor. Alternatively, the controller can be synchronized to an external clock generated to another MAX1875/MAX1876 or a system clock. One MAX1875/MAX1876 can be set to generate an in-phase, or 90° out-of-phase, clock signal for synchronization with additional controllers. This allows two controllers to operate either as an interleaved two- or four-phase system with each output shifted by 90°. These devices also feature soft-start and soft-stop.

The MAX1875/MAX1876 eliminate the need for current-sense resistors by utilizing the low-side MOSFET's on-resistance as a current-sense element. This protects the DC-DC components from damage during output- overload conditions or when output short-circuit faults without requiring a current-sense resistor. Adjustable foldback current limit reduces power dissipation during short-circuit conditions. The MAX1876 includes a power-on reset output to signal the system when both outputs reach regulation.

The MAX1875/MAX1876 are available in a 24-pin QSOP package. An evaluation kit is available to speed designs.

Key Features

Applications/Uses

	Two Independent Output Voltages
	180° Out-of-Phase Operation
	90° Out-of-Phase Operation (Using Two MAX1875/MAX1876s)
	Foldback Current Limit
	4.75V to 23V Input Supply Range
	0 to 18V Output-Voltage Range (Up to 10A)
	>90% Efficiency
	Fixed-Frequency Pulse-Width Modulation (PWM) Operation
	Adjustable 100kHz to 600kHz Switching Frequency
	External SYNC Input
	Clock Output for Master/Slave Synchronization
	Soft-Start and Soft-Stop
	Active-low RST Output with 140ms Minimum Delay (MAX1876)
	Lossless Current Limit (No Sense Resistor)

	Broadband Routers
	DSP, ASIC, and FPGA Power Supplies
	Network-Power Supplies
	Servers
	Set-Top Boxes
	Telecom Power Supplies

Key Specifications: Switch-Mode DC-DC Power Supplies

Part Number

Topology

V_IN (min) (V)

V_IN (max) (V)

Number of DC-DC Outputs

Digital/VID Programmed Output

Min. Adjustable V_OUT (V)

Max. Adjustable V_OUT (V)

I_OUT (A)

Operating Current, I_CC (max) (mA)

Fixed Freq/PWM Operation

Operating Freq. (kHz)

Internal Power Switch(es)

Synchronous Rectifier

Package

Smallest Available Package (max w/pins) (mm²)

Price^**

MAX1875

Step-Down

4.75

Yes

QSOP/24

$2.00 @ 1k

MAX1876

200
300
400
600

$2.30 @ 1k

See All Switch-Mode DC-DC Power Supplies (421)

Notes:
^**This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific prices and delivery, please see the price and availability page or contact an authorized distributor.

Ordering Information

Notes:

Other options and links for purchasing parts are listed at: http://www.maxim-ic.com/sales.
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Part number suffixes: T or T&R = tape and reel; + = RoHS/lead-free; # = RoHS/lead-exempt. More: SeeFull Data Sheet or Part Naming Conventions.
* Some packages have variations, listed on the drawing. "PkgCode/Variation" tells which variation the product uses. Note that "+", "#", "-" in the part number suffix describes RoHS status. Package drawings may show a different suffix character.

Devices: 1-10 of 10

MAX1875

Free
Sample

Buy

Package:	TYPE PINS FOOTPRINT
	DRAWING CODE/VAR *

Temp

RoHS/Lead-Free?
Materials Analysis

MAX1875EEG

QSOP;24 pin;54 mm²
Dwg: 21-0055G (PDF)
Use pkgcode/variation: E24-1*

-40°C to +85°C

RoHS/Lead-Free: No
Materials Analysis

MAX1875EEG+T

QSOP;24 pin;54 mm²
Dwg: 21-0055G (PDF)
Use pkgcode/variation: E24+1*

-40°C to +85°C

RoHS/Lead-Free: Lead Free
Materials Analysis

MAX1875EEG+

QSOP;24 pin;54 mm²
Dwg: 21-0055G (PDF)
Use pkgcode/variation: E24+1*

-40°C to +85°C

RoHS/Lead-Free: Lead Free
Materials Analysis

MAX1875EEG-T

QSOP;24 pin;54 mm²
Dwg: 21-0055G (PDF)
Use pkgcode/variation: E24-1*

-40°C to +85°C

RoHS/Lead-Free: No
Materials Analysis

MAX1876

Free
Sample

Buy

Package:	TYPE PINS FOOTPRINT
	DRAWING CODE/VAR *

Temp

RoHS/Lead-Free?
Materials Analysis

MAX1876EEG-G05

-40°C to +85°C

See data sheet

MAX1876EEG-TG05

QSOP;24 pin;54 mm²
Dwg: 21-0055G (PDF)
Use pkgcode/variation: E24-1*

-40°C to +85°C

RoHS/Lead-Free: No
Materials Analysis

MAX1876EEG-T

QSOP;24 pin;54 mm²
Dwg: 21-0055G (PDF)
Use pkgcode/variation: E24-1*

-40°C to +85°C

RoHS/Lead-Free: No
Materials Analysis

MAX1876EEG

QSOP;24 pin;54 mm²
Dwg: 21-0055G (PDF)
Use pkgcode/variation: E24-1*

-40°C to +85°C

RoHS/Lead-Free: No
Materials Analysis

MAX1876EEG+

QSOP;24 pin;54 mm²
Dwg: 21-0055G (PDF)
Use pkgcode/variation: E24+1*

-40°C to +85°C

RoHS/Lead-Free: Lead Free
Materials Analysis

MAX1876EEG+T

QSOP;24 pin;54 mm²
Dwg: 21-0055G (PDF)
Use pkgcode/variation: E24+1*

-40°C to +85°C

RoHS/Lead-Free: Lead Free
Materials Analysis