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
II. ........Manufacturing Information
III. .......Packaging Information
IV. .......Die Information
V. ........Quality Assurance Information
VI. .......Reliability Evaluation
......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
V+ to GND
VCC, VDD to GND
PGND to GND
TRIG, LIMIT to GND
ILIM, CM+, CM-, CS+, CS-, COMP to GND
DL to PGND
BST to GND
DH to LX
LX to BST
Operating Temperature Range
Junction Temperature
Storage Temperature Range
Lead Temperature (soldering, 10s)
Continuous Power Dissipation (TA = +70°C)
16-Pin QSOP
Derates above +70°C
10-Pin uMAX
Rating
-0.3V to +30V
-0.3V to +6V
±0.3V
-0.3V to +6V
-0.3V to (VCC + 0.3V)
-0.3V to (VDD + 0.3V)
-0.3V to +36V
-0.3V to (VBST + 0.3V)
-6V to +0.3V
-40°C to +85°C
+150°C
-65°C to +150°C
+300°C
667mW
8.3mW/°C
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