Datasheet LT3506, LT3506A (Analog Devices)
| Manufacturer | Analog Devices |
| Description | Dual Monolithic 1.6A Step-Down Switching Regulator |
| Pages / Page | 24 / 1 — FEATURES. DESCRIPTION. Wide Input Voltage Range, 3.6V to 25V. Two 1.6A … |
| File Format / Size | PDF / 221 Kb |
| Document Language | English |
FEATURES. DESCRIPTION. Wide Input Voltage Range, 3.6V to 25V. Two 1.6A Output Switching Regulators with Internal
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Text Version of Document
LT3506/LT3506A Dual Monolithic 1.6A Step-Down Switching Regulator
FEATURES DESCRIPTION
n
Wide Input Voltage Range, 3.6V to 25V
The LT®3506 is a dual current mode PWM step-down DC/DC n
Two 1.6A Output Switching Regulators with Internal
converter with internal 2A power switches. Both convert-
Power Switches
ers are synchronized to a single oscillator and run with n
Constant Switching Frequency
opposite phases, reducing input ripple current. The output
LT3506: 575kHz
voltages are set with external resistor dividers, and each
LT3506A: 1.1MHz
regulator has independent shutdown and soft-start circuits. n
Anti-Phase Switching Reduces Ripple
Each regulator generates a power-good signal when its n
Accurate 0.8V Reference, ±1%
output is in regulation, easing power supply sequencing n Independent Shutdown/Soft-Start Pins and interfacing with microcontrollers and DSPs. n Independent Power Good Indicators Ease Supply The LT3506 switching frequency is 575kHz and the LT3506A Sequencing is 1.1MHz. These high switching frequencies allow the n Uses Small Inductors and Ceramic Capacitors use of tiny inductors and capacitors, resulting in a very n Small 16-Lead Thermally Enhanced 5mm × 4mm small dual 1.6A output solution. Constant frequency and DFN and TSSOP Surface Mount Packages ceramic capacitors combine to produce low, predictable output ripple voltage. With its wide input range of 3.6V to
APPLICATIONS
25V, the LT3506 regulates a wide variety of power sources, from 4-cell batteries and 5V logic rails to unregulated wall n Disk Drives transformers, lead acid batteries and distributed-power n DSP Power Supplies supplies. Current mode PWM architecture provides fast n Wall Transformer Regulation transient response with simple compensation components n Distributed Power Regulation and cycle-by-cycle current limiting. Frequency foldback n DSL Modems and thermal shutdown provide additional protection. n Cable Modems 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.
TYPICAL APPLICATION Effi ciency
VIN 4.5V TO 25V 1/2 BAT-54A 100 VIN = 5V 22μF V V IN1 IN2 1/2 BAT-54A BOOST1 BOOST2 90 VOUT = 3.3V 4.7μH 0.22μF 0.22μF 6.4μH V V OUT1 OUT2 1.8V SW1 SW2 3.3V 1.6A 1.6A 80 VOUT = 1.8V 18.7k 33.2k FB1 FB2 1000pF 2200pF 70 V V C1 C2 EFFICIENCY (%) D1 D2 47μF 15k 15k LT3506 10k 10.7k 22μF 60 RUN/SS1 RUN/SS2 100k 1.5nF 1.5nF 3506 TA01a PGOOD1 50 0 0.5 1.0 1.5 2.0 100k PGOOD2 IOUT (A) 3506 TA01b D1, D2: ON SEMI MBR5230LT3 GND PGOOD1 PGOOD2 3506afc 1
FEATURES DESCRIPTION
n
Wide Input Voltage Range, 3.6V to 25V
The LT®3506 is a dual current mode PWM step-down DC/DC n
Two 1.6A Output Switching Regulators with Internal
converter with internal 2A power switches. Both convert-
Power Switches
ers are synchronized to a single oscillator and run with n
Constant Switching Frequency
opposite phases, reducing input ripple current. The output
LT3506: 575kHz
voltages are set with external resistor dividers, and each
LT3506A: 1.1MHz
regulator has independent shutdown and soft-start circuits. n
Anti-Phase Switching Reduces Ripple
Each regulator generates a power-good signal when its n
Accurate 0.8V Reference, ±1%
output is in regulation, easing power supply sequencing n Independent Shutdown/Soft-Start Pins and interfacing with microcontrollers and DSPs. n Independent Power Good Indicators Ease Supply The LT3506 switching frequency is 575kHz and the LT3506A Sequencing is 1.1MHz. These high switching frequencies allow the n Uses Small Inductors and Ceramic Capacitors use of tiny inductors and capacitors, resulting in a very n Small 16-Lead Thermally Enhanced 5mm × 4mm small dual 1.6A output solution. Constant frequency and DFN and TSSOP Surface Mount Packages ceramic capacitors combine to produce low, predictable output ripple voltage. With its wide input range of 3.6V to
APPLICATIONS
25V, the LT3506 regulates a wide variety of power sources, from 4-cell batteries and 5V logic rails to unregulated wall n Disk Drives transformers, lead acid batteries and distributed-power n DSP Power Supplies supplies. Current mode PWM architecture provides fast n Wall Transformer Regulation transient response with simple compensation components n Distributed Power Regulation and cycle-by-cycle current limiting. Frequency foldback n DSL Modems and thermal shutdown provide additional protection. n Cable Modems 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.
TYPICAL APPLICATION Effi ciency
VIN 4.5V TO 25V 1/2 BAT-54A 100 VIN = 5V 22μF V V IN1 IN2 1/2 BAT-54A BOOST1 BOOST2 90 VOUT = 3.3V 4.7μH 0.22μF 0.22μF 6.4μH V V OUT1 OUT2 1.8V SW1 SW2 3.3V 1.6A 1.6A 80 VOUT = 1.8V 18.7k 33.2k FB1 FB2 1000pF 2200pF 70 V V C1 C2 EFFICIENCY (%) D1 D2 47μF 15k 15k LT3506 10k 10.7k 22μF 60 RUN/SS1 RUN/SS2 100k 1.5nF 1.5nF 3506 TA01a PGOOD1 50 0 0.5 1.0 1.5 2.0 100k PGOOD2 IOUT (A) 3506 TA01b D1, D2: ON SEMI MBR5230LT3 GND PGOOD1 PGOOD2 3506afc 1
