TS1935 Просмотр технического описания (PDF) - TSC Corporation
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TS1935 Datasheet PDF : 8 Pages
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Function Block Diagram
TS1935
1.6MHz Boost Converter
with 30V Internal FET Switch
Pin Description
The TS1935 is a switching converter IC that operates at a fixed frequency (1.6MHz) for fast transient response over a
wide input voltage range and incorporates pulse-by-pulse current limiting protection. Because this is current mode
control, a 33mΩ sense resistor in series with the switch FET is used to provide a voltage (which is proportional to the
FET current) to both the input of the pulse width modulation (PWM) comparator and the current limit amplifier.
At the beginning of each cycle, the S-R lath turns on the FET. As the current through the FET increases, a voltage
(proportional to this current) is summed with the ramp coming from the ramp generator and then fed into the input of
the PWM comparator. When this voltage exceeds the voltage on the other input (coming from the Gm amplifier), the
latch resets and turns the FET off. Since the signal coming from the Gm amplifier is derived from the feedback (which
samples the voltage at the output), the action of the PWM comparator constantly sets the correct peak current through
the FET to keep the output voltage in regulation.
Q1 & Q2 align with R3 – R6 form a bandgap voltage reference used by the IC to hold the output in regulation. The
currents flowing through Q1 & Q2 will be equal, and the feedback loop will adjust the regulated output to maintain this .
Because of this, the regulated output is always maintained at a voltage level equal to the voltage at the FB node
“multiplied up” by the ratio of the output resistive divider.
The current limit comparator feeds directly into the flip-flop that derives the switch FET. If the FET current reaches the
limit threshold, the FET is turned off and the cycle terminates the pulse regardless of the status of the output of the
PWM comparator.
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Version: A07
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