Datasheet LTC3826 (Analog Devices)
| Manufacturer | Analog Devices |
| Description | 30µA IQ, Dual, 2-Phase Synchronous Step-Down Controller |
| Pages / Page | 36 / 1 — FEATURES. DESCRIPTION. Wide Output Voltage Range: 0.8V ≤ VOUT ≤ 10V. … |
| File Format / Size | PDF / 485 Kb |
| Document Language | English |
FEATURES. DESCRIPTION. Wide Output Voltage Range: 0.8V ≤ VOUT ≤ 10V. Ultralow Operating IQ: 30μA (One Channel On)
Model Line for this Datasheet
Text Version of Document
LTC3826 30µA IQ, Dual, 2-Phase Synchronous Step-Down Controller
FEATURES DESCRIPTION
n
Wide Output Voltage Range: 0.8V ≤ VOUT ≤ 10V
The LTC®3826 is a high performance dual step-down n
Ultralow Operating IQ: 30μA (One Channel On)
switching regulator controller that drives all N-channel n
Out-of-Phase Controllers Reduce Required Input
synchronous power MOSFET stages. A constant frequency
Capacitance and Power Supply Induced Noise
current mode architecture allows a phase-lockable fre- n
OPTI-LOOP® Compensation Minimizes COUT
quency of up to 650kHz. Power loss and noise due to the n
±1% Output Voltage Accuracy
ESR of the input capacitor are minimized by operating the n
Wide VIN Range: 4V to 36V Operation
two controller output stages out of phase. n
Phase-Lockable Fixed Frequency 140kHz to 650kHz
The 30μA no-load quiescent current extends operating n Selectable Continuous, Pulse Skipping or
Low Ripple
life in battery powered systems. OPTI-LOOP compensa- Burst Mode® Operation at Light Loads tion allows the transient response to be optimized over n Dual N-Channel MOSFET Synchronous Drive a wide range of output capacitance and ESR values. The n Very Low Dropout Operation: 99% Duty Cycle LTC3826 features a precision 0.8V reference and a power n Adjustable Output Voltage Soft-Start or Tracking good output indicator. A wide 4V to 36V input supply range n Output Current Foldback Limiting encompasses all battery chemistries. n Power Good Output Voltage Monitor n Output Overvoltage Protection Independent TRACK/SS pins for each controller ramp the n Low Shutdown I output voltage during start-up. Current foldback limits Q: 4μA n Internal LDO Powers Gate Drive from V MOSFET heat dissipation during short-circuit conditions. IN or VOUT n Small 5mm × 5mm QFN Package The PLLIN/MODE pin selects among Burst Mode opera- tion, pulse skipping mode, or continuous inductor cur-
APPLICATIONS
rent mode at light loads. For a leaded package version n Automotive Systems (28-lead SSOP), see the LTC3826-1 data sheet. n Battery-Operated Digital Devices L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. Burst Mode and OPTI-LOOP are registered trademarks of Linear Technology Corporation. n Distributed DC Power Systems All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 5481178, 5929620, 6177787, 6144194, 5408150, 6580258, 6304066, 5705919.
TYPICAL APPLICATION High Effi ciency Dual 8.5V/3.3V Step-Down Converter Effi ciency and Power Loss
V
vs Load Current
IN 4V TO 36V 22μF 100 10000 4.7μF 50V VIN INTVCC 90 TG1 TG2 80 1000 0.1μF POWER LOSS (mW) BOOST1 BOOST2 70 3.3μH 0.1μF 7.2μH SW1 SW2 60 100 BG1 BG2 50 LTC3826 PGND 40 10 EFFICIENCY (%) 30 SENSE1+ SENSE2+ 20 1 0.015Ω 0.015Ω 10 V SENSE1– SENSE2– FIGURE 13 CIRCUIT OUT1 VOUT2 0 0.1 3.3V VFB1 VFB2 8.5V 0.00001 0.0001 0.001 0.01 0.1 1 10 5A 62.5k 192.5k 3.5A ITH1 ITH2 OUTPUT CURRENT (A) 220pF 150μF 220pF TRACK/SS1 TRACK/SS2 150μF SGND 3826 TA01b 20k 20k 15k 15k 0.1μF 0.1μF 3826 TA01 3826fc 1
FEATURES DESCRIPTION
n
Wide Output Voltage Range: 0.8V ≤ VOUT ≤ 10V
The LTC®3826 is a high performance dual step-down n
Ultralow Operating IQ: 30μA (One Channel On)
switching regulator controller that drives all N-channel n
Out-of-Phase Controllers Reduce Required Input
synchronous power MOSFET stages. A constant frequency
Capacitance and Power Supply Induced Noise
current mode architecture allows a phase-lockable fre- n
OPTI-LOOP® Compensation Minimizes COUT
quency of up to 650kHz. Power loss and noise due to the n
±1% Output Voltage Accuracy
ESR of the input capacitor are minimized by operating the n
Wide VIN Range: 4V to 36V Operation
two controller output stages out of phase. n
Phase-Lockable Fixed Frequency 140kHz to 650kHz
The 30μA no-load quiescent current extends operating n Selectable Continuous, Pulse Skipping or
Low Ripple
life in battery powered systems. OPTI-LOOP compensa- Burst Mode® Operation at Light Loads tion allows the transient response to be optimized over n Dual N-Channel MOSFET Synchronous Drive a wide range of output capacitance and ESR values. The n Very Low Dropout Operation: 99% Duty Cycle LTC3826 features a precision 0.8V reference and a power n Adjustable Output Voltage Soft-Start or Tracking good output indicator. A wide 4V to 36V input supply range n Output Current Foldback Limiting encompasses all battery chemistries. n Power Good Output Voltage Monitor n Output Overvoltage Protection Independent TRACK/SS pins for each controller ramp the n Low Shutdown I output voltage during start-up. Current foldback limits Q: 4μA n Internal LDO Powers Gate Drive from V MOSFET heat dissipation during short-circuit conditions. IN or VOUT n Small 5mm × 5mm QFN Package The PLLIN/MODE pin selects among Burst Mode opera- tion, pulse skipping mode, or continuous inductor cur-
APPLICATIONS
rent mode at light loads. For a leaded package version n Automotive Systems (28-lead SSOP), see the LTC3826-1 data sheet. n Battery-Operated Digital Devices L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. Burst Mode and OPTI-LOOP are registered trademarks of Linear Technology Corporation. n Distributed DC Power Systems All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 5481178, 5929620, 6177787, 6144194, 5408150, 6580258, 6304066, 5705919.
TYPICAL APPLICATION High Effi ciency Dual 8.5V/3.3V Step-Down Converter Effi ciency and Power Loss
V
vs Load Current
IN 4V TO 36V 22μF 100 10000 4.7μF 50V VIN INTVCC 90 TG1 TG2 80 1000 0.1μF POWER LOSS (mW) BOOST1 BOOST2 70 3.3μH 0.1μF 7.2μH SW1 SW2 60 100 BG1 BG2 50 LTC3826 PGND 40 10 EFFICIENCY (%) 30 SENSE1+ SENSE2+ 20 1 0.015Ω 0.015Ω 10 V SENSE1– SENSE2– FIGURE 13 CIRCUIT OUT1 VOUT2 0 0.1 3.3V VFB1 VFB2 8.5V 0.00001 0.0001 0.001 0.01 0.1 1 10 5A 62.5k 192.5k 3.5A ITH1 ITH2 OUTPUT CURRENT (A) 220pF 150μF 220pF TRACK/SS1 TRACK/SS2 150μF SGND 3826 TA01b 20k 20k 15k 15k 0.1μF 0.1μF 3826 TA01 3826fc 1
