SY21035SXC (SY8521SXC)

High Efficiency, 0.6A, 100V Input Synchronous Step Down Regulator

SY21035SXC High Efficiency, 0.6A, 100V Input Synchronous Step Down Regulator Datasheet

Parameters
Features
Description

Part number	SY21035SXC
Channel(#)	1
Vin (min) (V)	7
Vin (max) (V)	100
Switching frequency (min)(kHz)	200
Switching frequency (max)(kHz)	1000
Vout (min) (V)	1.225
Vout (max) (V)	24
Iout (max) (A)	0.6
Vout2 (min)(V)
Vout2 (max )(V)
Iout2 (max)(A)
Vref accuracy (±%)	2(over temperature)
Vout accuracy(±%)
Control mode	COT+Ripple
Duty cycle (max)(%)	75
Operation mode	FCCM
Iq (typ) (uA)
Features
Package	DFN4×4-8
Operating temperature range(°C)	-40 to 125
Functional safety category

Low RDS(ON) for Internal Switches (Top/Bottom): 500mΩ/285mΩ
7-100V Input Voltage Range
0.6A Output Current Capability
Constant On-time Control
Instant PWM Architecture to Achieve Fast Transient Responses
Programmable Switching Frequency Range: 200kHz~1MHz.
2ms Internal Soft-start Limits the Inrush Current
Precise ±2% 1.225V Reference over -40°C to +125°C Temperature Range
Cycle-by-cycle Peak Current Limit
Over Temperature Protection with Auto Recovery
RoHS Compliant and Halogen Free
Compact Package DFN4×4-8

The SY8521 develops a high efficiency synchronous step-down DC/DC converter capable of delivering 0.6A current. The SY8521 operates over a wide input voltage range from 7V to 100V and integrates main switch and synchronous switch with very low RDS(ON) to minimize the conduction loss. The SY8521 always operates under continuous condition mode. The device adopts the instant PWM architecture to achieve fast transient responses for high step down applications.

Evaluation Board

Photo of evaluation board
Photo of evaluation board
Photo of evaluation board

EVB_SY21035SXC

EVB File

The EVB_SY21035SXC is intended for evaluating fast response, 0.6A, 100V input synchronous Buck regulator.

Design resources

Online Simulation

SY21035SXC

Technical Documentation

Title	Date
Silergy_Catalog_Q2_2026	2026-06-12
DFN4x4-8	2022-05-20