Datasheet LTC3828 (Analog Devices)
| Manufacturer | Analog Devices |
| Description | Dual, 2-Phase Step-Down Controller with Tracking |
| Pages / Page | 32 / 1 — FEATURES. DESCRIPTION. Dual, 180° Phased Controllers Reduce Required. … |
| File Format / Size | PDF / 388 Kb |
| Document Language | English |
FEATURES. DESCRIPTION. Dual, 180° Phased Controllers Reduce Required. Input Capacitance and Power Supply Induced Noise
Model Line for this Datasheet
Text Version of Document
LTC3828 Dual, 2-Phase Step-Down Controller with Tracking
FEATURES DESCRIPTION
n
Dual, 180° Phased Controllers Reduce Required
The LTC®3828 is a dual high performance step-down
Input Capacitance and Power Supply Induced Noise
switching regulator controller that drives all N-channel n
Tracking for Both Outputs
synchronous power MOSFET stages. A constant frequency n
Constant Frequency Current Mode Control
current mode architecture allows for a phase-lockable n
Wide VIN Range: 4.5V to 28V Operation
frequency of up to 550kHz. The TRCKSS pin provides both n
Power Good Output Voltage Indicator
soft-start and tracking functions. Multiple LTC3828s can n
Adjustable Soft-Start Current Ramping
be daisy-chained in applications requiring more than two n
Foldback Output Current Limiting–
voltages to be tracked.
Disabled at Start-Up
OPTI-LOOP compensation allows the transient response n
No Reverse Current During Soft-Start Interval
to be optimized over a wide range of output capacitance n Clock Output for 3-, 4-, 6-Phase Operation and ESR values. The precision 0.8V reference and power n Dual N-Channel MOSFET Synchronous Drive good output indicator are compatible with a wide 4.5V to n ±1% Output Voltage Accuracy 28V (30V maximum) input supply range, encompassing n Phase-Lockable Fixed Frequency 260kHz to 550kHz all battery chemistries. n OPTI-LOOP® Compensation Minimizes COUT n Very Low Dropout Operation: 99% Duty Cycle The RUN pins control their respective channels indepen- n Output Overvoltage Protection dently. The FCB/PLLIN pin selects among Burst Mode® n Small 28-Lead SSOP and 5mm × 5mm QFN operation, skip-cycle mode and continuous current mode. Packages Current foldback limits MOSFET dissipation during short- circuit conditions. Reverse current and current foldback
APPLICATIONS
functions are disabled during soft-start. n Telecom Infrastructure L, LT, LTC, LTM, Burst Mode and OPTI-LOOP are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. n ASIC Power Supply Protected by U.S. Patents including 5481178, 5705919, 5929620, 6144194, 6177787, 6304066, 6580258 n Industry Equipment
TYPICAL APPLICATION High Effi ciency Dual 2.5V/3.3V Step-Down Converter with Tracking
4.5V TO 28V + 22μF 1μF 4.7μF 50V CERAMIC CERAMIC VIN PGOOD INTVCC TG1 TG2 0.1μF 0.1μF BOOST1 BOOST2 3.2μH 3.2μH SW1 SW2 LTC3828 BG1 BG2 500kHz FCB/PLLIN PGND SENSE1+ SENSE2+ 0.01Ω 1000pF 1000pF 0.01Ω SENSE1– SENSE2– 3.3V 2.5V V 5A OSENSE1 VOSENSE2 5A 63.4k 1% 42.5k TRCKSS2 TRCKSS1 TRCKSS1 1% 63.4k 1% ITH1 ITH2 20k 20k 220pF 1% 1% 220pF + RUN1 SGND RUN2 47μF 20k + 56μF 4V 1% 15k 0.1μF 4V 15k SP SP 3828 TA01 3828fc 1
FEATURES DESCRIPTION
n
Dual, 180° Phased Controllers Reduce Required
The LTC®3828 is a dual high performance step-down
Input Capacitance and Power Supply Induced Noise
switching regulator controller that drives all N-channel n
Tracking for Both Outputs
synchronous power MOSFET stages. A constant frequency n
Constant Frequency Current Mode Control
current mode architecture allows for a phase-lockable n
Wide VIN Range: 4.5V to 28V Operation
frequency of up to 550kHz. The TRCKSS pin provides both n
Power Good Output Voltage Indicator
soft-start and tracking functions. Multiple LTC3828s can n
Adjustable Soft-Start Current Ramping
be daisy-chained in applications requiring more than two n
Foldback Output Current Limiting–
voltages to be tracked.
Disabled at Start-Up
OPTI-LOOP compensation allows the transient response n
No Reverse Current During Soft-Start Interval
to be optimized over a wide range of output capacitance n Clock Output for 3-, 4-, 6-Phase Operation and ESR values. The precision 0.8V reference and power n Dual N-Channel MOSFET Synchronous Drive good output indicator are compatible with a wide 4.5V to n ±1% Output Voltage Accuracy 28V (30V maximum) input supply range, encompassing n Phase-Lockable Fixed Frequency 260kHz to 550kHz all battery chemistries. n OPTI-LOOP® Compensation Minimizes COUT n Very Low Dropout Operation: 99% Duty Cycle The RUN pins control their respective channels indepen- n Output Overvoltage Protection dently. The FCB/PLLIN pin selects among Burst Mode® n Small 28-Lead SSOP and 5mm × 5mm QFN operation, skip-cycle mode and continuous current mode. Packages Current foldback limits MOSFET dissipation during short- circuit conditions. Reverse current and current foldback
APPLICATIONS
functions are disabled during soft-start. n Telecom Infrastructure L, LT, LTC, LTM, Burst Mode and OPTI-LOOP are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. n ASIC Power Supply Protected by U.S. Patents including 5481178, 5705919, 5929620, 6144194, 6177787, 6304066, 6580258 n Industry Equipment
TYPICAL APPLICATION High Effi ciency Dual 2.5V/3.3V Step-Down Converter with Tracking
4.5V TO 28V + 22μF 1μF 4.7μF 50V CERAMIC CERAMIC VIN PGOOD INTVCC TG1 TG2 0.1μF 0.1μF BOOST1 BOOST2 3.2μH 3.2μH SW1 SW2 LTC3828 BG1 BG2 500kHz FCB/PLLIN PGND SENSE1+ SENSE2+ 0.01Ω 1000pF 1000pF 0.01Ω SENSE1– SENSE2– 3.3V 2.5V V 5A OSENSE1 VOSENSE2 5A 63.4k 1% 42.5k TRCKSS2 TRCKSS1 TRCKSS1 1% 63.4k 1% ITH1 ITH2 20k 20k 220pF 1% 1% 220pF + RUN1 SGND RUN2 47μF 20k + 56μF 4V 1% 15k 0.1μF 4V 15k SP SP 3828 TA01 3828fc 1
