Datasheet LTC1879 (Analog Devices) - 3
| Manufacturer | Analog Devices |
| Description | 1.2A Synchronous Step-Down Regulator with 15µA Quiescent Current |
| Pages / Page | 20 / 3 — ELECTRICAL CHARACTERISTICS The |
| File Format / Size | PDF / 268 Kb |
| Document Language | English |
ELECTRICAL CHARACTERISTICS The
Model Line for this Datasheet
Text Version of Document
LTC1879
ELECTRICAL CHARACTERISTICS The
●
denotes specifications which apply over the full operating temperature range, otherwise specifications are TA = 25
°
C. VIN = 5V unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
VRUN RUN Threshold VRUN Ramping Up ● 0.2 0.7 1.5 V IRUN RUN Input Current VRUN = 0V ±0.01 ±1 µA
Note 1:
Absolute Maximum Ratings are those values beyond which the life
Note 4:
The LTC1879 is tested in a feedback loop which servos VFB to the of a device may be impaired. balance point for the error amplifier (VITH = 1.2V)
Note 2:
The LTC1879E is guaranteed to meet specified performance from
Note 5:
Dynamic supply current is higher due to the gate charge being 0°C to 70°C. Specifications over the – 40°C to 85°C operating ambient delivered at the switching frequency. temperature range are assured by design, characterization and correlation
Note 6:
This IC includes overtemperature protection that is intended to with statistical process controls. protect the device during momentary overload conditions. Junction
Note 3:
TJ is calculated from the ambient temperature TA and power temperature will exceed 125°C when overtemperature protection is active. dissipation PD according to the following formula: Continuous operation above the specified maximum operating junction LTC1879: T temperature may impair device reliability. J = TA + (PD × 140°C/W)
W U TYPICAL PERFOR A CE CHARACTERISTICS Oscillator Frequency Oscillator Frequency RDS(ON) vs Temperature vs Temperature vs Supply Voltage
0.7 595 600 SYNCHRONOUS SWITCH VIN = 5V 590 0.6 MAIN SWITCH V 575 580 IN = 5V 0.5 V 570 IN = 10V ) Ω 555 560 ( 0.4 550 DS(ON) 0.3 R 535 540 VIN = 5V FREQUENCY (kHz) 0.2 VIN = 10V 530 515 OSCILLATOR FREQUENCY (kHz) 520 0.1 510 0 495 500 –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125 2 4 6 8 10 TEMPERATURE (°C) TEMPERATURE (°C) SUPPLY VOLTAGE (V) 1879 G01 1879 G02 1879 G03
DC Supply Current DC Supply Current vs Temperature vs Input Voltage RDS(ON) vs Input Voltage
300 300 0.6 VIN = 5V 250 250 0.5 PULSE SKIPPING MODE µA) PULSE SKIPPING MODE SYNCHRONOUS µA) SWITCH 200 200 0.4 ) Ω ( 150 150 0.3 MAIN DS(ON) SWITCH R 100 100 0.2 SUPPLY CURRENT ( DC SUPPLY CURRENT ( 50 50 0.1 Burst Mode OPERATON Burst Mode OPERATION 0 0 0 –50 0 50 100 125 0 2 4 6 8 10 2 3 4 5 6 7 8 9 10 TEMPERATURE (°C) INPUT VOLTAGE (V) INPUT VOLTAGE (V) 1879 G04 1879 G05 1879 G06 1879f 3
ELECTRICAL CHARACTERISTICS The
●
denotes specifications which apply over the full operating temperature range, otherwise specifications are TA = 25
°
C. VIN = 5V unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
VRUN RUN Threshold VRUN Ramping Up ● 0.2 0.7 1.5 V IRUN RUN Input Current VRUN = 0V ±0.01 ±1 µA
Note 1:
Absolute Maximum Ratings are those values beyond which the life
Note 4:
The LTC1879 is tested in a feedback loop which servos VFB to the of a device may be impaired. balance point for the error amplifier (VITH = 1.2V)
Note 2:
The LTC1879E is guaranteed to meet specified performance from
Note 5:
Dynamic supply current is higher due to the gate charge being 0°C to 70°C. Specifications over the – 40°C to 85°C operating ambient delivered at the switching frequency. temperature range are assured by design, characterization and correlation
Note 6:
This IC includes overtemperature protection that is intended to with statistical process controls. protect the device during momentary overload conditions. Junction
Note 3:
TJ is calculated from the ambient temperature TA and power temperature will exceed 125°C when overtemperature protection is active. dissipation PD according to the following formula: Continuous operation above the specified maximum operating junction LTC1879: T temperature may impair device reliability. J = TA + (PD × 140°C/W)
W U TYPICAL PERFOR A CE CHARACTERISTICS Oscillator Frequency Oscillator Frequency RDS(ON) vs Temperature vs Temperature vs Supply Voltage
0.7 595 600 SYNCHRONOUS SWITCH VIN = 5V 590 0.6 MAIN SWITCH V 575 580 IN = 5V 0.5 V 570 IN = 10V ) Ω 555 560 ( 0.4 550 DS(ON) 0.3 R 535 540 VIN = 5V FREQUENCY (kHz) 0.2 VIN = 10V 530 515 OSCILLATOR FREQUENCY (kHz) 520 0.1 510 0 495 500 –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125 2 4 6 8 10 TEMPERATURE (°C) TEMPERATURE (°C) SUPPLY VOLTAGE (V) 1879 G01 1879 G02 1879 G03
DC Supply Current DC Supply Current vs Temperature vs Input Voltage RDS(ON) vs Input Voltage
300 300 0.6 VIN = 5V 250 250 0.5 PULSE SKIPPING MODE µA) PULSE SKIPPING MODE SYNCHRONOUS µA) SWITCH 200 200 0.4 ) Ω ( 150 150 0.3 MAIN DS(ON) SWITCH R 100 100 0.2 SUPPLY CURRENT ( DC SUPPLY CURRENT ( 50 50 0.1 Burst Mode OPERATON Burst Mode OPERATION 0 0 0 –50 0 50 100 125 0 2 4 6 8 10 2 3 4 5 6 7 8 9 10 TEMPERATURE (°C) INPUT VOLTAGE (V) INPUT VOLTAGE (V) 1879 G04 1879 G05 1879 G06 1879f 3
