LT3667 Series

40V 400mA Step-Down Switching Regulator with Dual Fault Protected LDOs

Catalog

40V 400mA Step-Down Switching Regulator with Dual Fault Protected LDOs

Part	Mounting Type	Package / Case	Voltage/Current - Output 1 [Min]	Voltage/Current - Output 1	Voltage/Current - Output 1 [Max]	Voltage/Current - Output 3 [Min]	Voltage/Current - Output 3	Voltage/Current - Output 3 [Max]	Voltage/Current - Output 2 [Min]	Voltage/Current - Output 2 [Max]	Voltage/Current - Output 2	Number of Outputs	Supplier Device Package	Voltage - Supply [Max]	Voltage - Supply [Min]	Topology	Frequency - Switching [Min]	Frequency - Switching [Max]	Operating Temperature [Max]	Operating Temperature [Min]	Package / Case
Analog Devices LT3667HUDD#TRPBF	Surface Mount	24-WFQFN Exposed Pad	1.2 V	400 mA	38.6 V	0.8 V	200 mA	38.6 V	0.8 V	38.6 V	200 mA	3	24-QFN (3x5)	45 V	1.6 V	Linear (LDO) (2) Step-Down (Buck) (1)	243 kHz	2.2 MHz
Analog Devices LT3667EMSE#TRPBF	Surface Mount	16-TFSOP Exposed Pad	1.2 V	400 mA	38.6 V	0.8 V	200 mA	38.6 V	0.8 V	38.6 V	200 mA	3	16-MSOP-EP	45 V	1.6 V	Linear (LDO) (2) Step-Down (Buck) (1)	243 kHz	2.2 MHz	125 °C	-40 °C	0.118 in 3 mm
Analog Devices LT3667EUDD#PBF	Surface Mount	24-WFQFN Exposed Pad	1.2 V	400 mA	38.6 V	0.8 V	200 mA	38.6 V	0.8 V	38.6 V	200 mA	3	24-QFN (3x5)	45 V	1.6 V	Linear (LDO) (2) Step-Down (Buck) (1)	243 kHz	2.2 MHz	125 °C	-40 °C
Analog Devices LT3667IUDD#PBF	Surface Mount	24-WFQFN Exposed Pad	1.2 V	400 mA	38.6 V	0.8 V	200 mA	38.6 V	0.8 V	38.6 V	200 mA	3	24-QFN (3x5)	45 V	1.6 V	Linear (LDO) (2) Step-Down (Buck) (1)	243 kHz	2.2 MHz	125 °C	-40 °C
Analog Devices LT3667IUDD	Surface Mount	24-WFQFN Exposed Pad	1.2 V	400 mA	38.6 V	0.8 V	200 mA	38.6 V	0.8 V	38.6 V	200 mA	3	24-QFN (3x5)	45 V	1.6 V	Linear (LDO) (2) Step-Down (Buck) (1)	243 kHz	2.2 MHz	125 °C	-40 °C
Analog Devices LT3667HMSE#TRPBF	Surface Mount	16-TFSOP Exposed Pad	1.2 V	400 mA	38.6 V	0.8 V	200 mA	38.6 V	0.8 V	38.6 V	200 mA	3	16-MSOP-EP	45 V	1.6 V	Linear (LDO) (2) Step-Down (Buck) (1)	243 kHz	2.2 MHz			0.118 in 3 mm
Analog Devices LT3667IMSE#PBF	Surface Mount	16-TFSOP Exposed Pad	1.2 V	400 mA	38.6 V	0.8 V	200 mA	38.6 V	0.8 V	38.6 V	200 mA	3	16-MSOP-EP	45 V	1.6 V	Linear (LDO) (2) Step-Down (Buck) (1)	243 kHz	2.2 MHz	125 °C	-40 °C	0.118 in 3 mm

Catalog

40V 400mA Step-Down Switching Regulator with Dual Fault Protected LDOs

Key Features

• Triple Output Supply from a Single Input Requires Only One Inductor

• IQ= 50μA at 12VINto 5V, 3.3V and 2.5V with No Load

• Buck Regulator:Low Ripple (<15mVP-P) Burst Mode Operation®400mA Output with Internal Power Switch4.3V to 40V Input Operation Range (60V Max)

• Low Ripple (<15mVP-P) Burst Mode Operation®

• 400mA Output with Internal Power Switch

• 4.3V to 40V Input Operation Range (60V Max)

• Dual Low Dropout Linear Regulators200mA Outputs with Programmable Current Limits1.6V to 45V Input RangeFault Protected to ±45V

• 200mA Outputs with Programmable Current Limits

• 1.6V to 45V Input Range

• Fault Protected to ±45V

• Adjustable 250kHz to 2.2MHz Switching Frequency

• Synchronizable Between 300kHz and 2.2MHz

• Programmable Undervoltage Lockout

• Power Good Indicators

• Available in a Thermally-Enhanced 16-Lead MSOP and 24-Lead (3mm × 5mm) QFN Packages

Description

The LT3667 is a monolithic triple power supply composed of a 400mA buck switching regulator and two 200mA low dropout linear regulators (LDOs).The buck regulator includes a high efficiency switch, a boost diode, and the necessary oscillator, control and logic circuitry. Current mode topology is used for fast transient response and good loop stability. Low ripple Burst Mode operation maintains high efficiency at low output currents while keeping output ripple below 15mV in a typical application.Each LDO supplies 200mA of output current with a typical dropout voltage of 340mV, and each LDO has an accurate resistor programmable current limit.Internal protection circuitry includes reverse-battery protection, current limiting, thermal limiting and reverse current protection.The LT3667 is available in a thermally-enhanced 16-Lead MSOP and a 24-Pin 3mm x 5mm QFN package with exposed pad for low thermal resistance.ApplicationsAutomotive Battery RegulationPower for Portable InstrumentationIndustrial SuppliesFault-Protected Sensor Supply