max5071aauat Maxim Integrated Products, Inc., max5071aauat Datasheet - Page 11

• Manufacturer Part Number: max5071aauat
• Description: High-performance, Single-ended, Current-mode Pwm Controllers
• Manufacturer: Maxim Integrated Products, Inc.

Figure 1. MAX5070A/MAX5070B Functional Diagram
The MAX5070/MAX5071 current-mode PWM controllers
are designed for use as the control and regulation core of
flyback or forward topology switching power supplies.
These devices incorporate an integrated low-side driver,
adjustable oscillator, error amplifier (MAX5070A/
MAX5070B only), current-sense amplifier, 5V reference,
and external synchronization capability (MAX5071A/
MAX5071B only). An internal +26.5V current-limited V
clamp prevents overvoltage during startup.
Five different versions of the MAX5070/MAX5071 are
available. The MAX5070A/MAX5070B are the standard
High-Performance, Single-Ended, Current-Mode
COMP
GND
MAX5070A/MAX5070B
CS
FB
3
5
2
1
VEA
______________________________________________________________________________________
Detailed Description
2R
1V
EN-DRV-BAR
ILIM
R
CPWM
DELAY
REFERENCE
2.5V
CC
2.5V
2.5V
REG_OK
versions with a feedback input (FB) and internal error
amplifier. The MAX5071A/MAX5071B include bidirection-
al synchronization (SYNC). This enables multiple
MAX5071A/MAX5071Bs to be connected and synchro-
nized to the device with the highest frequency. The
MAX5071C includes an ADV_CLK output, which pre-
cedes the MAX5071C’s drive output (OUT) by 110ns.
Figures 1, 2, and 3 show the internal functional diagrams
of the MAX5070A/MAX5070B, MAX5071A/MAX5071B,
and MAX5071C, respectively. The MAX5070A/
MAX5071A are capable of 100% maximum duty cycle.
The MAX5070B/MAX5071B/MAX5071C are designed to
limit the maximum duty cycle to 50%.
OSC Q
PREREGULATOR
VP
5V
CLK
PWM Controllers
SHUTDOWN
THERMAL
S
R
Q
EN-REF
BG
SNS
100% MAX DUTY CYCLE (MAX5070A)
50% MAX DUTY CYCLE (MAX5070B)
VP
UVLO
5V REGULATOR
VOLTAGE-
DIVIDER
16V/10V
V
DD
VOLTAGE-
DIVIDER
26.5V
7
8
6 OUT
4 R
V
VREF
CC
T
/C
T
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