RY8411

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©RYCHIP Semiconductor Inc.

Standoff 42V 1.2A 800KHz Sync Step-Down Regulator

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Functional Block Diagram

Bias&Ref

Regulator

Error Amplifier

Slope

Compensation

Comparator

Fault

Detection

0.8/2MHz

Clock

OTP

Driver

Valley Curve

Detection

Peak Curve

Detection

EN

FB

IN

BS

SW

GND

Block Diagram

Functions Description

Internal Regulator

The RY8411 is a current mode step down DC/DC converter that provides excellent transient response with no extra

external compensation components. This device contains an internal, low resistance, high voltage power MOSFET,

and operates at a high 800KHz operating frequency to ensure a compact, high efficiency design with excellent AC

and DC performance.

Error Amplifier

The error amplifier compares the FB pin voltage with the internal FB reference (VFB) and outputs a current

proportional to the difference between the two. This output current is then used to charge or discharge the internal

compensation network, which is used to control the power MOSFET current. The optimized internal compensation

network minimizes the external component counts and simplifies the control loop design.

Under-Voltage Lockout (UVLO)

Under-voltage lockout (UVLO) protects the chip from operating at an insufficient supply voltage. UVLO protection

monitors the internal regulator voltage. When the voltage is lower than UVLO threshold voltage, the device is shut

off. When the voltage is higher than UVLO threshold voltage, the device is enabled again.

Thermal Shutdown

Thermal shutdown prevents the chip from operating at exceedingly high temperatures. When the silicon die

temperature exceeds 150°C, it shuts down the whole chip. When the temperature falls below its lower threshold

(Typ. 130°C) the chip is enabled again.