Rainbow Electronics MAX5095A - Manual

General Description
The MAX5094A/B/C/D/MAX5095A/B/C BiCMOS, high-
performance, current-mode PWM controllers have all the
features required for wide input-voltage range
isolated/nonisolated power supplies. These controllers
are used for low- and high-power universal input volt-
age and telecom power supplies.
The MAX5094/MAX5095 contain a fast comparator with
only 60ns typical delay from current sense to the output
for overcurrent protection. The MAX5094 has an inte-
grated error amplifier with the output at COMP. Soft-
start is achieved by controlling the COMP voltage rise
using external components.
The oscillator frequency is adjustable from 20kHz to
1MHz with an external resistor and capacitor. The tim-
ing capacitor discharge current is trimmed allowing for
programmable dead time and maximum duty cycle for
a given frequency. The available saw-toothed waveform
at R
T C T can be used for slope compensation when
needed.
The MAX5095A/MAX5095B include a bidirectional syn-
chronization circuit allowing for multiple controllers to
run at the same frequency to avoid beat frequencies.
Synchronization is accomplished by simply connecting
the SYNC of all devices together. When synchronizing
with other devices, the MAX5095A/MAX5095B with the
highest frequency synchronizes the other devices.
Alternatively, the MAX5095A/MAX5095B can be syn-
chronized to an external clock with an open-drain out-
put stage running at a higher frequency.
The MAX5095C provides a clock output pulse
(ADV_CLK) that leads the driver output (OUT) by
110ns. The advanced clock signal is used to drive the
secondary-side synchronous rectifiers.
The MAX5094A/B/C are available in the 8-pin SO and
8-pin µMAX
® packages. The MAX5094D and
MAX5095A/B/C are available in the 8-pin µMAX pack-
age. All devices operate over the automotive tempera-
ture range of -40°C to +125°C.
Applications
Universal Input AC/DC Power Supplies
Isolated Telecom Power Supplies
Isolated Power-Supply Modules
Networking Systems
Computer Systems/Servers
Industrial Power Conversion
Isolated Keep-Alive Circuits
Features
♦ Pin-for-Pin Replacement for UCC28C43
(MAX5094A) and UCC28C45 (MAX5094B)
♦ 2A Drive Source and 1A Sink Capability
♦ Up to 1MHz Switching Frequency Operation
♦ Bidirectional Frequency Synchronization
(MAX5095A/MAX5095B)
♦ Advanced Output Drive for Secondary-Side
Synchronous Rectification (MAX5095C)
♦ Fast 60ns Cycle-by-Cycle Current Limit
♦ Trimmed Oscillator Capacitor Discharge Current
Sets Maximum Duty Cycle Accurately
♦ Accurate ±5% Start Voltage with 0.8V Hysteresis
♦ Low 32µA Startup Current
♦ 5V Regulator Output (REF) with 20mA Capability
♦ Versions with 0.3V Current-Sense Threshold
MAX5094A/B/C/D/MAX5095A/B/C
High-Performance, Single-Ended, Current-Mode
PWM Controllers
________________________________________________________________ Maxim Integrated Products 1
OUT
GND R T /C T
1
2
8
7
REF
V CC FB
CS
COMP
µMAX/SO
TOP VIEW
3
4
6
5
MAX5094
Pin Configurations
Ordering Information
19-3864; Rev 0; 10/05
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
PART TEMP RANGE
PIN-
PACKAGE PKG
CODE
MAX5094AASA -40°C to +125°C 8 SO S8-4
MAX5094AAUA -40°C to +125°C 8 µMAX U8-1
MAX5094BASA* -40°C to +125°C 8 SO S8-4
MAX5094BAUA* -40°C to +125°C 8 µMAX U8-1
MAX5094CASA* -40°C to +125°C 8 SO S8-4
MAX5094CAUA* -40°C to +125°C 8 µMAX U8-1
MAX5094DAUA* -40°C to +125°C 8 µMAX U8-1
MAX5095AAUA -40°C to +125°C 8 µMAX U8-1
MAX5095BAUA* -40°C to +125°C 8 µMAX U8-1
MAX5095CAUA* -40°C to +125°C 8 µMAX U8-1
Pin Configurations continued at end of data sheet.
µMAX is a registered trademark of Maxim Integrated Products, Inc.
*Future product—contact factory for availability.
Ordering Information continued at end of data sheet.