Datasheet LTC3409A (Analog Devices)
| Manufacturer | Analog Devices |
| Description | 600mA Low VIN Buck Regulator in 3mm × 3mm DFN |
| Pages / Page | 16 / 1 — FEATURES. DESCRIPTION. 1.6V to 5.5V Input Voltage Range. 0.62V to 5.5V … |
| File Format / Size | PDF / 321 Kb |
| Document Language | English |
FEATURES. DESCRIPTION. 1.6V to 5.5V Input Voltage Range. 0.62V to 5.5V Output Voltage Range. Internal Soft-Start
Model Line for this Datasheet
Text Version of Document
LTC3409A 600mA Low VIN Buck Regulator in 3mm × 3mm DFN
FEATURES DESCRIPTION
n
1.6V to 5.5V Input Voltage Range
The LTC®3409A is a high effi ciency, monolithic synchronous n
0.62V to 5.5V Output Voltage Range
buck regulator using a constant frequency, current mode n
Internal Soft-Start
architecture. The LTC3409A improves upon the LTC3409’s n
Selectable 1.7MHz or 2.6MHz Constant Frequency
light load regulation in Burst Mode operation. The output
Operation
voltage is adjusted via an external resistor divider. n
Internal Oscillator Can Be Synchronized to an
Fixed switching frequencies of 1.7MHz and 2.6MHz are
External Clock, 1MHz to 3MHz Range
supported. Alternatively, an internal PLL will synchronize n High Effi ciency: Up to 95% to an external clock in the frequency range of 1MHz to n 65μA Quiescent Current, Burst Mode® Operation 3MHz. This range of switching frequencies allows the n 600mA Output Current (VIN = 1.8V, VOUT = 1.2V) use of small surface mount inductors and capacitors, n 750mA Peak Inductor Current including ceramics. n No Schottky Diode Required n Low Dropout Operation: 100% Duty Cycle Supply current during Burst Mode operation is only n 0.612V Reference Voltage 65μA dropping to <1μA in shutdown. The 1.6V to 5.5V n Stable with Ceramic Capacitors input voltage range makes the LTC3409A ideally suited n Shutdown Mode Draws <1μA Supply Current for single cell Li-Ion, Li-Metal and 2-cell alkaline, NiCd n Current Mode Operation for Excellent Line and Load or NiMH battery-powered applications. 100% duty cycle Transient Response capability provides low dropout operation, extending bat- n Overtemperature Protection tery life in portable systems. Burst Mode operation can be n Available in a Low Profi le (0.75mm) user-enabled, increasing effi ciency at light loads, further 8-Lead (3mm × 3mm) DFN Package extending battery life. The internal synchronous switch increases effi ciency and eliminates the need for an external Schottky diode. Internal
APPLICATIONS
soft-start offers controlled output voltage rise time at start- n Cellular Phones up without the need for external components. n Digital Cameras n MP3 Players L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 5481178, 6580258, 6304066, 6127815, 6498466, 6611131.
TYPICAL APPLICATION Burst Mode Effi ciency, 1.8VOUT High Effi ciency Step-Down Converter
100 1 90 2.5VIN, BURST LTC3409A 2.2μH* 80 V V IN OUT 0.1 VIN SW 1.8V TO 5.5V 1.8V 70 POWER LOSS (W) 10pF 4.7μF RUN 22μF 60 3.6VIN, BURST 267k s2 MODE VFB 50 0.01 4.2V 137k IN, BURST SYNC GND 40 EFFICIENCY (%) POWER LOST 30 3.6VIN, BURST *SUMIDA CDRH2D18/LD 0.001 3409A TA01 20 10 0 0.0001 0 1 10 100 1000 LOAD CURRENT (mA) 3409A TA01b 3409af 1
FEATURES DESCRIPTION
n
1.6V to 5.5V Input Voltage Range
The LTC®3409A is a high effi ciency, monolithic synchronous n
0.62V to 5.5V Output Voltage Range
buck regulator using a constant frequency, current mode n
Internal Soft-Start
architecture. The LTC3409A improves upon the LTC3409’s n
Selectable 1.7MHz or 2.6MHz Constant Frequency
light load regulation in Burst Mode operation. The output
Operation
voltage is adjusted via an external resistor divider. n
Internal Oscillator Can Be Synchronized to an
Fixed switching frequencies of 1.7MHz and 2.6MHz are
External Clock, 1MHz to 3MHz Range
supported. Alternatively, an internal PLL will synchronize n High Effi ciency: Up to 95% to an external clock in the frequency range of 1MHz to n 65μA Quiescent Current, Burst Mode® Operation 3MHz. This range of switching frequencies allows the n 600mA Output Current (VIN = 1.8V, VOUT = 1.2V) use of small surface mount inductors and capacitors, n 750mA Peak Inductor Current including ceramics. n No Schottky Diode Required n Low Dropout Operation: 100% Duty Cycle Supply current during Burst Mode operation is only n 0.612V Reference Voltage 65μA dropping to <1μA in shutdown. The 1.6V to 5.5V n Stable with Ceramic Capacitors input voltage range makes the LTC3409A ideally suited n Shutdown Mode Draws <1μA Supply Current for single cell Li-Ion, Li-Metal and 2-cell alkaline, NiCd n Current Mode Operation for Excellent Line and Load or NiMH battery-powered applications. 100% duty cycle Transient Response capability provides low dropout operation, extending bat- n Overtemperature Protection tery life in portable systems. Burst Mode operation can be n Available in a Low Profi le (0.75mm) user-enabled, increasing effi ciency at light loads, further 8-Lead (3mm × 3mm) DFN Package extending battery life. The internal synchronous switch increases effi ciency and eliminates the need for an external Schottky diode. Internal
APPLICATIONS
soft-start offers controlled output voltage rise time at start- n Cellular Phones up without the need for external components. n Digital Cameras n MP3 Players L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 5481178, 6580258, 6304066, 6127815, 6498466, 6611131.
TYPICAL APPLICATION Burst Mode Effi ciency, 1.8VOUT High Effi ciency Step-Down Converter
100 1 90 2.5VIN, BURST LTC3409A 2.2μH* 80 V V IN OUT 0.1 VIN SW 1.8V TO 5.5V 1.8V 70 POWER LOSS (W) 10pF 4.7μF RUN 22μF 60 3.6VIN, BURST 267k s2 MODE VFB 50 0.01 4.2V 137k IN, BURST SYNC GND 40 EFFICIENCY (%) POWER LOST 30 3.6VIN, BURST *SUMIDA CDRH2D18/LD 0.001 3409A TA01 20 10 0 0.0001 0 1 10 100 1000 LOAD CURRENT (mA) 3409A TA01b 3409af 1
