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MAX5070, MAX5071
High-Performance, Single-Ended, Current-Mode PWM Controllers
1MHz, Single-Ended, Current-Mode PWM Controllers Pin Compatible with UC2842/UC2844 Series
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Status
Active: In Production.
Description
The MAX5070/MAX5071 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 voltage and telecom power
supplies.
The MAX5070/MAX5071 contain a fast comparator with
only 60ns typical delay from current sense to the output
for overcurrent protection. The MAX5070A/MAX5070B
have an integrated error amplifier with the output at
COMP. Soft-start is achieved by controlling the COMP
voltage rise using external components.
The frequency is adjustable from 20kHz to 1MHz with
an external resistor and capacitor. The timing capacitor
discharge current is trimmed allowing for programmable
dead time and maximum duty cycle for a given frequency.
The available saw-toothed waveform at RTCT
can be used for slope compensation when needed.
The MAX5071A/MAX5071B include a bidirectional synchronization
circuit allowing for multiple controllers to
run at the same frequency to avoid beat frequencies.
Synchronization is accomplished by simply connecting
the SYNC pins of all devices together. When synchronizing
with other devices, the MAX5071A/MAX5071B
with the highest frequency synchronizes the other
devices. Alternatively, the MAX5071A/MAX5071B can
be synchronized to an external clock with an opendrain
output stage running at a higher frequency.
The MAX5071C 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 MAX5070/MAX5071 are available in 8-pin µMAX®
and SO packages and operate over the automotive temperature
range of -40°C to +125°C.
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Data Sheet
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Key Features
- Pin-for-Pin Replacement for UC2842 (MAX5070A) and UC2844 (MAX5070B)
- 2A Drive Source and 1A Sink Capability
- Up to 1MHz Switching Frequency Operation
- Bidirectional Synchronization (MAX5071A/MAX5071B)
- Advanced Output Drive for Secondary-Side Synchronous Rectification (MAX5071C)
- Fast 60ns Cycle-by-Cycle Current Limit
- Trimmed Oscillator Capacitor Discharge Current Sets Maximum Duty Cycle Accurately
- Accurate 5% Start and Stop Voltage with 6V Hysteresis
- Low 32µA Startup Current
- 5V Regulator Output (VREF) with 20mA Capability
- Overtemperature Shutdown
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Applications/Uses
- Computer Systems/Servers
- Industrial Power Conversion
- Isolated Keep-Alive Circuits
- Isolated Power Supplies
- Isolated Telecom Power Supplies
- Networking Systems
- Universal Input AC/DC Power Supplies
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Key Specifications:
| Isolated Power Supplies |
| Part Number |
Application (VIN) |
VIN
(V) |
VIN
(V) |
Topology |
Feedback |
Freq.
(kHz) |
Duty Cycle
(%) |
ISTARTUP
(mA) |
ICC
(mA) |
Gate Drive Current
(A) |
Oper. Temp.
(°C) |
Budgetary Price |
| min |
max |
min |
max |
max |
max |
max |
See Notes |
| MAX5070 |
| Base Station (24V) | | Industrial (24V) | | Networking (48V) | | Power Over Ethernet (32-58V) | | Telecom (36-72V) | | Universal Off-line (90-240VAC) |
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11 |
26.5 |
| Flyback | | Single-Ended Forward |
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1000 |
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0.032 |
3 |
2 |
-40 to +125 |
$1.09 @1k |
| MAX5071 |
Single-Ended Forward |
$1.18 @1k |
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See All Isolated Power Supplies (26)
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Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific prices and delivery, please see the price and availability page or contact an authorized distributor.
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Diagram
Pin Configuration
Pin Configuration
More Information
Didn't Find What You Need?
Information Index
Document Ref.: 19-3283
Rev 3;
2006-10-23
This page last modified: 2009-10-12
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