Design DocumentAnalog

DC3251A: LTC3302A 2A Synchronous Step-Down Regulator Evaluation Board

Evaluation board for the LTC3302A 2A synchronous buck regulator, featuring a 2MHz Silent Switcher architecture, EMI filter, and load-transient evaluation circuit.

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Overview

The DC3251A is a demonstration circuit for the LTC3302A, a compact 5V, 2A synchronous monolithic step-down switching regulator. The board is configured to operate at 2MHz, converting a 3.3V input to a 1.2V output, though it supports input voltages from 2.25V to 5.5V and adjustable outputs from 0.5V to VIN. It utilizes Silent Switcher technology for high efficiency and includes an EMI filter designed to meet CISPR25 Class 5 peak limits. The evaluation kit supports multiple operating modes, including Burst Mode, pulse skip, and forced continuous mode, and features a specialized circuit for load-transient evaluation.

Use Cases

High-efficiency point-of-load regulation
EMI-sensitive automotive applications
Compact consumer electronics power management
High-speed switching power conversion
Industrial low-voltage power systems

Topics

LTC3302A

DC3251A

Synchronous Step-Down Regulator

Silent Switcher

Buck Regulator

EMI Filter

CISPR25 Class 5

Analog Devices

FCQFN

Load Transient Evaluation

Referenced Parts

04025A330JAT2A

AVX

Capacitor, 33 pF, C0G, 50 V, 5%, 0402

LTC6908HS6-1#TRMPBF

Analog Devices

IC, oscillator silicon programmable, TSOT-23-6

2308-2-00-80-00-00-07-0

Mill-Max

Test points, turret, 0.064" mounting hole diameter

2501-2-00-80-00-00-07-0

Mill-Max

Test points, turret, 0.094" mounting hole diameter

GCM155C71A105KE38D

Murata

Capacitor, 1 μF, X7S, 10 V, 10%, 0402, AEC-Q200

GCM155R71A104KA55D

Murata

Capacitor, 0.1 μF, X7R, 10 V, 10%, 0402, AEC-Q200

GRT033D70J105ME13D

Murata

Capacitor, 1 μF, X7T, 6.3 V, 20%, 0201, AEC-Q200

GRT188D71A106ME13D

Murata

Capacitors, 10 μF, X7T, 10 V, 20%, 0603, AEC-Q200

NRC04F2002TRF

NIC Components

Resistor, 20 kΩ, 1%, 1/16 W, 0402, AEC-Q200

NRC04F20R0TRF

NIC Components

Resistor, 20 Ω, 1%, 1/16 W, 0402, AEC-Q200

NRC04F2493TRF

NIC Components

Resistor, 249 kΩ, 1%, 1/16 W, 0402, AEC-Q200

NRC04J103TRF

NIC Components

Resistor, 10 kΩ, 5%, 1/16 W, 0402, AEC-Q200

6TPE330ML

Panasonic

Capacitors, 330 μF, Tantalum, POSCAP TPE, 6.3 V, 20%, 7343, 25 mΩ

ERJ2GEJ103X

Panasonic

Resistor, 10 kΩ, 5%, 1/10 W, 0402, AEC-Q200

MPZ2012S101ATD25

TDK

Inductor, ferrite bead, 100 Ω at 100 MHz, 25%, 4 A, 20 mΩ, 0805, AEC-Q200

CRCW040214K3FKED

Vishay

Resistor, 14.3 kΩ, 1%, 1/16 W, 0402

SIR426DP-T1-GE3

Vishay

Transistor, N-MOSFET, 40 V, 15.9 A, PPAK SO-8

NRC04F4992TRF

NIC Components

Resistor, 49.9 kΩ, 1%, 1/16 W, 0402, AEC-Q200

60800213421

Wurth Electronics

Connectors, shunt, female, 2 position, 2 mm

744383430068

Wurth Electronics

Inductor, 680 nH, power, 20%, 2 A, 65 mΩ, 0806, AEC-Q200

LTC3302ARUCM#TRPBF

Analog Devices

IC, 5 V, 2 A, 2 MHz, synchronous step-down regulator

U.FL-R-SMT-1(10

Hirose Electric

Connector, U.FL, RCPT, male, ST, 3.0 mm × 3.1 mm, SMD, 50 Ω

500X07W102MV4T

Johanson Dielectrics

Capacitor, 1000 pF, X7R, 50 V, 20%, 0402, 3-Term, X2Y EMI filter

8833

Keystone

Standoff, nylon, snap-on, 0.50"

RMCF0402FT1M00

Stackpole Electronics

Resistor, 1 mΩ, 1%, 1/16 W, 0402, AEC-Q200

TFM201610ALMAR68MTAA

TDK

Inductor, 680 nH, power, 20%, 4.3 A, 53 mΩ, 0806, AEC-Q200

LRC-LR2512LF-01-R100-F

TT Electronics

Resistor, 0.1 Ω, 1%, 2 W, 2512, sense, AEC-Q200

62000311121

Wurth Elektronik

Connector, HDR, male, 1 × 3, 2 mm, vertical, straight, THT

62000411121

Wurth Elektronik

Connector, HDR, male, 1 × 4, 2 mm, vertical, straight, THT

RC0402JR-07100KL

Yageo

Resistor, 100 kΩ, 5%, 1/16 W, 0402

04025A330JAT2A	AVX	Capacitor, 33 pF, C0G, 50 V, 5%, 0402
LTC6908HS6-1#TRMPBF	Analog Devices	IC, oscillator silicon programmable, TSOT-23-6
2308-2-00-80-00-00-07-0	Mill-Max	Test points, turret, 0.064" mounting hole diameter
2501-2-00-80-00-00-07-0	Mill-Max	Test points, turret, 0.094" mounting hole diameter
GCM155C71A105KE38D	Murata	Capacitor, 1 μF, X7S, 10 V, 10%, 0402, AEC-Q200
GCM155R71A104KA55D	Murata	Capacitor, 0.1 μF, X7R, 10 V, 10%, 0402, AEC-Q200
GRT033D70J105ME13D	Murata	Capacitor, 1 μF, X7T, 6.3 V, 20%, 0201, AEC-Q200
GRT188D71A106ME13D	Murata	Capacitors, 10 μF, X7T, 10 V, 20%, 0603, AEC-Q200
NRC04F2002TRF	NIC Components	Resistor, 20 kΩ, 1%, 1/16 W, 0402, AEC-Q200
NRC04F20R0TRF	NIC Components	Resistor, 20 Ω, 1%, 1/16 W, 0402, AEC-Q200
NRC04F2493TRF	NIC Components	Resistor, 249 kΩ, 1%, 1/16 W, 0402, AEC-Q200
NRC04J103TRF	NIC Components	Resistor, 10 kΩ, 5%, 1/16 W, 0402, AEC-Q200
6TPE330ML	Panasonic	Capacitors, 330 μF, Tantalum, POSCAP TPE, 6.3 V, 20%, 7343, 25 mΩ
ERJ2GEJ103X	Panasonic	Resistor, 10 kΩ, 5%, 1/10 W, 0402, AEC-Q200
MPZ2012S101ATD25	TDK	Inductor, ferrite bead, 100 Ω at 100 MHz, 25%, 4 A, 20 mΩ, 0805, AEC-Q200
CRCW040214K3FKED	Vishay	Resistor, 14.3 kΩ, 1%, 1/16 W, 0402
SIR426DP-T1-GE3	Vishay	Transistor, N-MOSFET, 40 V, 15.9 A, PPAK SO-8
NRC04F4992TRF	NIC Components	Resistor, 49.9 kΩ, 1%, 1/16 W, 0402, AEC-Q200
60800213421	Wurth Electronics	Connectors, shunt, female, 2 position, 2 mm
744383430068	Wurth Electronics	Inductor, 680 nH, power, 20%, 2 A, 65 mΩ, 0806, AEC-Q200
LTC3302ARUCM#TRPBF	Analog Devices	IC, 5 V, 2 A, 2 MHz, synchronous step-down regulator
U.FL-R-SMT-1(10	Hirose Electric	Connector, U.FL, RCPT, male, ST, 3.0 mm × 3.1 mm, SMD, 50 Ω
500X07W102MV4T	Johanson Dielectrics	Capacitor, 1000 pF, X7R, 50 V, 20%, 0402, 3-Term, X2Y EMI filter
8833	Keystone	Standoff, nylon, snap-on, 0.50"
RMCF0402FT1M00	Stackpole Electronics	Resistor, 1 mΩ, 1%, 1/16 W, 0402, AEC-Q200
TFM201610ALMAR68MTAA	TDK	Inductor, 680 nH, power, 20%, 4.3 A, 53 mΩ, 0806, AEC-Q200
LRC-LR2512LF-01-R100-F	TT Electronics	Resistor, 0.1 Ω, 1%, 2 W, 2512, sense, AEC-Q200
62000311121	Wurth Elektronik	Connector, HDR, male, 1 × 3, 2 mm, vertical, straight, THT
62000411121	Wurth Elektronik	Connector, HDR, male, 1 × 4, 2 mm, vertical, straight, THT
RC0402JR-07100KL	Yageo	Resistor, 100 kΩ, 5%, 1/16 W, 0402