Datasheet LTC3670 (Analog Devices)
| Manufacturer | Analog Devices |
| Description | Monolithic 400mA Buck Regulator with Dual 150mA LDOs in 3mm × 2mm DFN |
| Pages / Page | 14 / 1 — FEATURES. DESCRIPTION. Triple Output Supply from a Single 2.5V to 5.5V … |
| Revision | A |
| File Format / Size | PDF / 401 Kb |
| Document Language | English |
FEATURES. DESCRIPTION. Triple Output Supply from a Single 2.5V to 5.5V Input. 400mA Buck DC/DC Plus Dual 150mA LDOs in One IC
Model Line for this Datasheet
Text Version of Document
LTC3670 Monolithic 400mA Buck Regulator with Dual 150mA LDOs in 3mm × 2mm DFN
FEATURES DESCRIPTION
n
Triple Output Supply from a Single 2.5V to 5.5V Input
The LTC®3670 is a triple power supply composed of a n
400mA Buck DC/DC Plus Dual 150mA LDOs in One IC
400mA synchronous buck regulator and two 150mA low n
Outputs Regulate Down to 0.8V
dropout linear regulators (LDOs). The input supply range n
±2.5% Reference Accuracy
of 2.5V to 5.5V is especially well-suited for single-cell n
Constant-Frequency 2.25MHz Operation
Lithium-Ion and Lithium-Ion/Polymer applications, and n
Burst Mode
®
Operation for High Efficiency at Light
for powering low voltage ASICs and SoCs from 3V, 3.3V
Loads; IQ = 70µA, All Outputs Enabled
or 5V rails. Regulated output voltages are programmed n
Independent Enable Pin for Each Output
via external resistors. Each output has its own enable pin n Current Mode Operation for Excellent Line and Load for maximum flexibility. Transient Response The 400mA buck regulator features constant-frequency n Internal Soft-Start for Each Output 2.25MHz operation, allowing small surface mount induc- n Tiny 12-Lead 3mm × 2mm × 0.75mm DFN Package tors and capacitors to be used. Burst Mode operation
APPLICATIONS
maintains high efficiency in light-load and no-load con- ditions. Internal control-loop compensation simplifies n Handheld Products application design. n Portable Instruments The LTC3670 is available in a 0.75mm profile, 3mm × 2mm n Single-Cell Li-Ion/Li-Polymer Powered Devices 12-lead DFN package. n DMB/DVB-H Multimedia Cell Phones n Multivoltage Power for Digital Logic, I/O, FPGAs, All registered trademarks and trademarks are the property of their respective owners. CPLDs, ASICs, SoCs, CPUs and RF Chipsets
TYPICAL APPLICATION Triple Power Supply with Independent Enables Demoboard
VIN 3.3V TO 5.5V 2.2µF VIN 4.7µH VOUT1 GND SW 1.2V 232k 400mA 10pF 4.7µF BUCKFB 464k LTC3670
9.3mm
VOUT2 ENBUCK LDO1 2.8V DIGITAL ENLDO1 150mA
9.4mm
CONTROL 806k 1µF ENLDO2
ACTIVE AREA
PGOOD LDO1_FB 324k VOUT3 LDO2 3.3V 3670 TA01b 1.02M 150mA 1µF LDO2_FB 324k 3670 TA01a Rev A Document Feedback For more information www.analog.com 1 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Typical Application Related Parts
FEATURES DESCRIPTION
n
Triple Output Supply from a Single 2.5V to 5.5V Input
The LTC®3670 is a triple power supply composed of a n
400mA Buck DC/DC Plus Dual 150mA LDOs in One IC
400mA synchronous buck regulator and two 150mA low n
Outputs Regulate Down to 0.8V
dropout linear regulators (LDOs). The input supply range n
±2.5% Reference Accuracy
of 2.5V to 5.5V is especially well-suited for single-cell n
Constant-Frequency 2.25MHz Operation
Lithium-Ion and Lithium-Ion/Polymer applications, and n
Burst Mode
®
Operation for High Efficiency at Light
for powering low voltage ASICs and SoCs from 3V, 3.3V
Loads; IQ = 70µA, All Outputs Enabled
or 5V rails. Regulated output voltages are programmed n
Independent Enable Pin for Each Output
via external resistors. Each output has its own enable pin n Current Mode Operation for Excellent Line and Load for maximum flexibility. Transient Response The 400mA buck regulator features constant-frequency n Internal Soft-Start for Each Output 2.25MHz operation, allowing small surface mount induc- n Tiny 12-Lead 3mm × 2mm × 0.75mm DFN Package tors and capacitors to be used. Burst Mode operation
APPLICATIONS
maintains high efficiency in light-load and no-load con- ditions. Internal control-loop compensation simplifies n Handheld Products application design. n Portable Instruments The LTC3670 is available in a 0.75mm profile, 3mm × 2mm n Single-Cell Li-Ion/Li-Polymer Powered Devices 12-lead DFN package. n DMB/DVB-H Multimedia Cell Phones n Multivoltage Power for Digital Logic, I/O, FPGAs, All registered trademarks and trademarks are the property of their respective owners. CPLDs, ASICs, SoCs, CPUs and RF Chipsets
TYPICAL APPLICATION Triple Power Supply with Independent Enables Demoboard
VIN 3.3V TO 5.5V 2.2µF VIN 4.7µH VOUT1 GND SW 1.2V 232k 400mA 10pF 4.7µF BUCKFB 464k LTC3670
9.3mm
VOUT2 ENBUCK LDO1 2.8V DIGITAL ENLDO1 150mA
9.4mm
CONTROL 806k 1µF ENLDO2
ACTIVE AREA
PGOOD LDO1_FB 324k VOUT3 LDO2 3.3V 3670 TA01b 1.02M 150mA 1µF LDO2_FB 324k 3670 TA01a Rev A Document Feedback For more information www.analog.com 1 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Typical Application Related Parts
