MAX1625

Better than ±1% Output Accuracy Over Line and Load
90% Efficiency
Excellent Transient Response
Resistor-Programmable Fixed Switching Frequency from 100kHz to 1MHz
Over 35A Output Current
Digitally Programmable Output from 1.1V to 3.5V in 100mV Increments (MAX1624)
Resistor-Adjustable Output down to 1.1V (MAX1625)
Remote Sensing
Adjustable AC Loop Gain (MAX1624)
GlitchCatcher™ Circuit for Fast Load-Transient Response (MAX1624)
Power-Good (PWROK) Output
Current-Mode Feedback
Digital Soft-Start
Strong 2A Gate Drivers
Current-Limited Output

Pentium Pro™, Pentium II™, PowerPC™, Alpha™, and K6™ Systems Desktop Computers LAN Servers Industrial Computers GTL Bus Termination

VDD, VCC, PWROK to AGND .................................................................-0.3V to 6V
PGND to AGND ............................................................................................±0.3V
CSH, CSL to AGND.................................................................-0.3V to (VCC + 0.3V
NDRV, PDRV, DL to PGND......................................................-0.3V to (VDD + 0.3V)
REF, CC1, CC2, LG, D0D4, FREQ,
FB to AGND..........................................................................-0.3V to (VCC + 0.3V)
BST to PGND .....................................................................................-0.3V to 12V
BST to LX ............................................................................................-0.3V to 6V
DH to LX.......................................................................(LX - 0.3V) to (BST + 0.3V)
Continuous Power Dissipation (TA = ±70°C)
24 Pin SSOP (derate 8.00mW/°C above +70°C) ....................................640mW
16 Pin Narrow SO (derate 8.70mW/°C above 70°C)..............................696mW
Operating Temperature Range
MAX162_E_ _............................................................................-40°C to +85°C
Storage Temperature Range ..................................................-65°C to +125°C
Lead Temperature (soldering, 10sec) ....................................................+300°C

Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.

The MAX1624/MAX1625 are ultra-high-performance, step-down DC-DC controllers for CPU power in high-end computer systems. Designed for demanding applications in which output voltage precision and good transient response are critical for proper operation, they deliver over 35A from 1.1V to 3.5V with ±1% total accuracy from a +5V ±10% supply. Excellent dynamic response corrects output transients caused by the latest dynamically clocked CPUs. These controllers achieve over 90% efficiency by using synchronous rectification. Flying-capacitor bootstrap circuitry drives inexpensive, external N-channel MOSFETs.

The switching frequency is resistor programmable from 100kHz to 1MHz. High switching frequencies allow the use of a small surface-mount inductor and decrease output filter capacitor requirements, reducing board area and system cost.

The MAX1624 is available in a 24-pin SSOP and offers additional features such as a digitally programmable output in 100mV increments; adjustable transient response; selectable 0.5%, 1%, or 2% AC load regulation; and gate drive for a current-boost MOSFET. The MAX1625 is resistor adjustable and comes in a 16-pin narrow SO package. Other features in both controllers include internal digital soft-start, a power-good output, and a 3.5V ±1% reference output. For a similar controller compatible with the latest Intel VRM/VID specification, see the MAX1638* data sheet.