Product Summary

The LM2638MX is a Motherboard Power Supply Solution with a 5-Bit Programmable Switching Controller and Two Linear Regulator Controllers. The LM2638MX provides a comprehensive embedded power supply solution for motherboards hosting high performance MPUs such as Pentium II, M II, K6-2 and other similar high performance MPUs. The LM2638MX incorporates a 5-bit programmable, synchronous buck switching controller and two high-speed linear regulator controllers in a 24-pin SO package. In a typical application, the switching controller supplies the MPU core, and the linear regulator controllers supply the GTL+ bus and the clock or graphics chip core. A charge pump pin helps provide the necessary voltage to power the linear sections when 12V is shut off during system standby such as STR mode. Applications include: Embedded power supplies for motherboards, Triple DC/DC power supplies, and Programmable high current DC/DC power supply.

Parametrics

LM2638MX absolute maximum ratings: (1)VCC: 7V; (2)VDD: 17V; (3)Junction Temperature: 150℃; (4)Power Dissipation: 1.6W; (5)Storage Temperature: 65℃ to +150℃; (6)ESD Susceptibility: 3 kV; (7)Soldering Time, Temperature (10 sec.): 300℃.

Features

LM2638MX features: (1)Provides 3 regulated voltages; (2)Power Good flag and output enable; (3)Charge pump pin Switching Section; (4)Synchronous rectification; (5)5-bit DAC programmable down to 1.3V; (6)Typical ±1% DAC tolerance; (7)Switching frequency: 50 kHz to 1 MHz; (8)Over-voltage protection; (9)Two methods of over-current protection; (10)Adaptive non-overlapping FET gate drives; (11)Soft start without external capacitor Linear Section; (12)N-FET and NPN drive capability; (13)Ultra fast response speed; (14)Under voltage latch-off at 0.63V; (15)Output voltages default to 1.5V and 2.5V yet adjustable.

Diagrams

LM2638MX block diagram

Image Part No Mfg Description Data Sheet Download Pricing
(USD)
Quantity
LM2638MX
LM2638MX


IC MOTHERBRD PWR SUPPLY 24-SOIC

Data Sheet

Negotiable 
Image Part No Mfg Description Data Sheet Download Pricing
(USD)
Quantity
LM26
LM26

Other


Data Sheet

Negotiable 
LM26001
LM26001

Other


Data Sheet

Negotiable 
LM26001BMH/NOPB
LM26001BMH/NOPB

National Semiconductor (TI)

Switching Converters, Regulators & Controllers

Data Sheet

0-1: $3.61
1-25: $2.90
25-100: $2.65
100-250: $2.38
LM26001BMHX/NOPB
LM26001BMHX/NOPB

National Semiconductor (TI)

Switching Converters, Regulators & Controllers

Data Sheet

0-1400: $1.72
1400-2500: $1.72
LM26001EVAL
LM26001EVAL

National Semiconductor (TI)

Power Management IC Development Tools EVAL BD FOR LM26001

Data Sheet

0-1: $57.44
LM26001MXA
LM26001MXA

National Semiconductor (TI)

Switching Converters, Regulators & Controllers

Data Sheet

0-184: $2.85
184-276: $2.62
276-552: $2.39
552-1012: $2.00