Datasheet LTC3802 (Analog Devices)
| Manufacturer | Analog Devices |
| Description | Dual 550kHz Synchronous 2-Phase DC/DC Controller with Programmable Up/Down Tracking |
| Pages / Page | 28 / 1 — FEATURES. DESCRIPTIO. Wide VIN Range: 3V to 30V Operation with Line. … |
| File Format / Size | PDF / 359 Kb |
| Document Language | English |
FEATURES. DESCRIPTIO. Wide VIN Range: 3V to 30V Operation with Line. Feedforward Compensation
Model Line for this Datasheet
Text Version of Document
LTC3802 Dual 550kHz Synchronous 2-Phase DC/DC Controller with Programmable Up/Down Tracking
U FEATURES DESCRIPTIO
■
Wide VIN Range: 3V to 30V Operation with Line
The LTC®3802 is a dual switching regulator controller
Feedforward Compensation
optimized for high efficiency step-down conversion from ■
Leading Edge Modulation Architecture for
input voltages between 3V to 30V. The controller uses a
Extremely Low Duty Cycle Operation
leading edge modulation scheme to allow extremely low ■
Phase-Lockable Fixed Frequency: 330kHz to 750kHz
duty cycle operation. The constant frequency voltage mode ■
Two 180
°
Out-of-Phase Controllers
controller allows a phase-lockable frequency between ■
Fast Programmable Power-Up/-Down Tracking
330kHz and 750kHz. Power loss and noise due to the ESR ■ Programmable Current Limit Without External of the input capacitors are minimized by operating the two Current Sense Resistor controller output stages 180° out of phase. The synchro- ■ Optional Burst Mode® Operation at Light Load nous buck architecture automatically shifts to Burst Mode ■ ±1% 0.6V Voltage Reference operation as the output load decreases, ensuring maxi- ■ External N-Channel MOSFET Architecture mum efficiency over a wide range of load currents. ■ Low Shutdown Current: <100µA The LTC3802 features an onboard, trimmed 0.6V refer- ■ Overvoltage Protection and PGOOD Flag ence and provides better than 1% regulation at the con- ■ Small 28-Lead SSOP and 32-Lead QFN Packages verter outputs. A separate output sense provides real time
U
overvoltage protection and PGOOD sensing. An FBT pin
APPLICATIO S
programs the power-up/-down tracking between the two ■ Notebook and Palmtop Computers channels to meet various sequencing requirements. A ■ Portable Instruments RUN/SS pin provides soft-start and externally program- ■ Battery-Operated Digital Devices mable current limit protection functions. ■ DC Power Distribution Systems , LTC and LT are registered trademarks of Linear Technology Corporation. Burst Mode is a registered trademark of Linear Technology Corporation. U.S. Patent Nos 5481178, 5846544, 6304066, 6580258, 5055767, 6307356
U TYPICAL APPLICATIO
VIN 5V TO 22V + 56µF 4.7µF 5V 25V 25V + CMDSH-3 ×2 ×8 CMDSH-3 10µF Si7860DP Si7860DP ×2 TG1 PV ×2 CC TG2 1 V µH OUT1 BOOST2 1µH VOUT2 3.3V 0.1µF 0.1µF 2.5V 15A BOOST1 SW2 B340B 15A Si7440DP B340B SW1 BG2 10k 10k + 330µF ×2 330µF + BG1 PLLIN 10k 10k 4V Si7440DP PGND PLLLPF 4V ×3 ×2 47k 47k ×3 LTC3802 I I MAX1 MAX2 560pF 3.16k 3.16k FBT CMPIN2 2.21k 2.21k CMPIN1 VCC 5V 1500pF 2200pF 10 + Ω COMP1 COMP2 560pF 390Ω 15k 0.1µF 10µF FB1 FB2 330pF SGND PHASEMD 2200pF 1500pF 15k 390Ω FCB VINFF RUN/SS PGOOD 330pF 3802 TA01 0.1 10k µF V 5V IN 0.47µF 3802f 1
U FEATURES DESCRIPTIO
■
Wide VIN Range: 3V to 30V Operation with Line
The LTC®3802 is a dual switching regulator controller
Feedforward Compensation
optimized for high efficiency step-down conversion from ■
Leading Edge Modulation Architecture for
input voltages between 3V to 30V. The controller uses a
Extremely Low Duty Cycle Operation
leading edge modulation scheme to allow extremely low ■
Phase-Lockable Fixed Frequency: 330kHz to 750kHz
duty cycle operation. The constant frequency voltage mode ■
Two 180
°
Out-of-Phase Controllers
controller allows a phase-lockable frequency between ■
Fast Programmable Power-Up/-Down Tracking
330kHz and 750kHz. Power loss and noise due to the ESR ■ Programmable Current Limit Without External of the input capacitors are minimized by operating the two Current Sense Resistor controller output stages 180° out of phase. The synchro- ■ Optional Burst Mode® Operation at Light Load nous buck architecture automatically shifts to Burst Mode ■ ±1% 0.6V Voltage Reference operation as the output load decreases, ensuring maxi- ■ External N-Channel MOSFET Architecture mum efficiency over a wide range of load currents. ■ Low Shutdown Current: <100µA The LTC3802 features an onboard, trimmed 0.6V refer- ■ Overvoltage Protection and PGOOD Flag ence and provides better than 1% regulation at the con- ■ Small 28-Lead SSOP and 32-Lead QFN Packages verter outputs. A separate output sense provides real time
U
overvoltage protection and PGOOD sensing. An FBT pin
APPLICATIO S
programs the power-up/-down tracking between the two ■ Notebook and Palmtop Computers channels to meet various sequencing requirements. A ■ Portable Instruments RUN/SS pin provides soft-start and externally program- ■ Battery-Operated Digital Devices mable current limit protection functions. ■ DC Power Distribution Systems , LTC and LT are registered trademarks of Linear Technology Corporation. Burst Mode is a registered trademark of Linear Technology Corporation. U.S. Patent Nos 5481178, 5846544, 6304066, 6580258, 5055767, 6307356
U TYPICAL APPLICATIO
VIN 5V TO 22V + 56µF 4.7µF 5V 25V 25V + CMDSH-3 ×2 ×8 CMDSH-3 10µF Si7860DP Si7860DP ×2 TG1 PV ×2 CC TG2 1 V µH OUT1 BOOST2 1µH VOUT2 3.3V 0.1µF 0.1µF 2.5V 15A BOOST1 SW2 B340B 15A Si7440DP B340B SW1 BG2 10k 10k + 330µF ×2 330µF + BG1 PLLIN 10k 10k 4V Si7440DP PGND PLLLPF 4V ×3 ×2 47k 47k ×3 LTC3802 I I MAX1 MAX2 560pF 3.16k 3.16k FBT CMPIN2 2.21k 2.21k CMPIN1 VCC 5V 1500pF 2200pF 10 + Ω COMP1 COMP2 560pF 390Ω 15k 0.1µF 10µF FB1 FB2 330pF SGND PHASEMD 2200pF 1500pF 15k 390Ω FCB VINFF RUN/SS PGOOD 330pF 3802 TA01 0.1 10k µF V 5V IN 0.47µF 3802f 1
