Conclusion

The MAX1887 successfully meets the quality and reliability standards required of all Maxim products. In addition,

Maxim’s continuous reliability monitoring program ensures that all outgoing product will continue to meet Maxim’s quality

and reliability standards.

Table of Contents

I. ........Device Description

V. ........Quality Assurance Information

II. ........Manufa cturing Information

VI. .......Reliability Evaluation

III. .......Packaging Information

IV. .......Die Information

......Attachments

I. Device Description

A. General

The MAX1887 step-down slave controller is intended for low-voltage, high-current, multiphase DC-to-DC applications.

The MAX1887 slave controller can be combined with any of Maxim's Quick-PWM™ step-down controllers to form a

multiphase DC-to-DC converter. Existing Quick-PWM controllers, such as the MAX1718, function as the master

controller, providing accurate output voltage regulation, fast transient response, and fault protection features.

Synchronized to the master's low-side gate driver, the MAX1887 includes the Quick-PWM constant on-time

controller, gate drivers for a synchronous rectifier, active current balancing, and precision current-limit circuitry.

The MAX1887 provides the same high efficiency, ultra-low duty factor capability, and excellent transient response as

other Quick-PWM controllers. The MAX1887 differentially senses the inductor currents of both the master and the

slave across current-sense resistors. These differential inputs and the adjustable current-limit threshold derived from

an external reference allow the slave controller to accurately balance the inductor currents and provide precise

current-limit protection. The MAX1887's dual-purpose current-limit input also allows the slave controller to

automatically enter a low-power standby mode when the master controller shuts down.

The MAX1887 triggers on the rising edge of the master's low-side gate driver, which staggers the on-times of both

master and slave, providing out-of-phase operation that can reduce the input ripple current and consequently the

number of input capacitors.

B. Absolute Maximum Ratings

Item

Rating

V+ to GND

-0.3V to +30V

VCC, VDD to GND

-0.3V to +6V

PGND to GND

±0.3V

TRIG, LIMIT to GND

-0.3V to +6V

ILIM, CM+, CM-, CS+, CS-, COMP to GND

-0.3V to (VCC + 0.3V)

DL to PGND

-0.3V to (VDD + 0.3V)

BST to GND

-0.3V to +36V

DH to LX

-0.3V to (VBST + 0.3V)

LX to BST

-6V to +0.3V

Operating Temperature Range

-40°C to +85°C

Junction Temperature

+150°C

Storage Temperature Range

-65°C to +150°C

Lead Temperature (soldering, 10s)

+300°C

Continuous Power Dissipation (TA = +70

°C)

16-Pin QSOP

667mW

Derates above +70

°C

10-Pin uMAX

8.3mW/

°C