Datasheet LTC3407-4 (Analog Devices) - 5
| Hersteller | Analog Devices |
| Beschreibung | Dual Synchronous, 800mA, 2.25MHz Step-Down DC/DC Regulator |
| Seiten / Seite | 16 / 5 — TYPICAL PERFORMANCE CHARACTERISTICS. Effi ciency vs Load Current. Line … |
| Dateiformat / Größe | PDF / 275 Kb |
| Dokumentensprache | Englisch |
TYPICAL PERFORMANCE CHARACTERISTICS. Effi ciency vs Load Current. Line Regulation. PIN FUNCTIONS VFB1 (Pin 1):. SW2 (Pin 7):
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LTC3407-4
TYPICAL PERFORMANCE CHARACTERISTICS Effi ciency vs Load Current Effi ciency vs Load Current Line Regulation
100 100 0.8 VOUT = 1.8V 90 V V IN = 3.6V IN = 2.7V 0.6 IOUT = 200mA T 80 A = 25°C V V IN = 4.2V IN = 2.7V 90 V 0.4 IN = 3.6V 70 0.2 60 VIN = 4.2V 0 50 80 ERROR (%) –0.2 40 EFFICIENCY (%) EFFICIENCY (%) OUTV –0.4 30 70 20 –0.6 VOUT = 1.2V VOUT = 1.5V 10 Burst Mode OPERATION Burst Mode OPERATION –0.8 NO LOAD ON OTHER CHANNEL NO LOAD ON OTHER CHANNEL 0 60 –1.0 1 10 100 1000 1 10 100 1000 2 3 4 5 6 LOAD CURRENT (mA) LOAD CURRENT (mA) VIN (V) 34074 G13 34074 G14 34074 G15
PIN FUNCTIONS VFB1 (Pin 1):
Output Feedback. Receives the feedback volt- synchronized to an external oscillator applied to this pin age from the external resistive divider across the output. and pulse-skipping mode is automatically selected. Nominal voltage for this pin is 0.6V.
SW2 (Pin 7):
Regulator 2 Switch Node Connection to the
RUN1 (Pin 2):
Regulator 1 Enable. Forcing this pin to VIN Inductor. This pin swings from VIN to GND. enables regulator 1, while forcing it to GND causes regulator
POR (Pin 8):
Power-On Reset . This common-drain logic 1 to shut down. This pin must be driven; do not fl oat. output is pulled to GND when the output voltage is not
VIN (Pin 3):
Main Power Supply. Must be closely decoupled within ±8.5% of regulation and goes high after 29ms when to GND. both channels are within regulation.
SW1 (Pin 4):
Regulator 1 Switch Node Connection to the
RUN2 (Pin 9):
Regulator 2 Enable. Forcing this pin to VIN Inductor. This pin swings from VIN to GND. enables regulator 2, while forcing it to GND causes regulator 2 to shut down. This pin must be driven; do not fl oat.
GND (Pin 5):
Ground. This pin is not connected internally. Connect to PCB ground for shielding.
VFB2 (Pin 10):
Output Feedback. Receives the feedback voltage from the external resistive divider across the output.
MODE/SYNC (Pin 6):
Combination Mode Selection and Nominal voltage for this pin is 0.6V. Oscillator Synchronization. This pin controls the opera- tion of the device. When tied to VIN or GND, Burst Mode
Exposed Pad (GND) (Pin 11):
Power Ground. Connect to operation or pulse-skipping mode is selected, respectively. the (–) terminal of COUT, and (–) terminal of CIN. Must be Do not fl oat this pin. The oscillation frequency can be connected to electrical ground on PCB. 34074fa 5
TYPICAL PERFORMANCE CHARACTERISTICS Effi ciency vs Load Current Effi ciency vs Load Current Line Regulation
100 100 0.8 VOUT = 1.8V 90 V V IN = 3.6V IN = 2.7V 0.6 IOUT = 200mA T 80 A = 25°C V V IN = 4.2V IN = 2.7V 90 V 0.4 IN = 3.6V 70 0.2 60 VIN = 4.2V 0 50 80 ERROR (%) –0.2 40 EFFICIENCY (%) EFFICIENCY (%) OUTV –0.4 30 70 20 –0.6 VOUT = 1.2V VOUT = 1.5V 10 Burst Mode OPERATION Burst Mode OPERATION –0.8 NO LOAD ON OTHER CHANNEL NO LOAD ON OTHER CHANNEL 0 60 –1.0 1 10 100 1000 1 10 100 1000 2 3 4 5 6 LOAD CURRENT (mA) LOAD CURRENT (mA) VIN (V) 34074 G13 34074 G14 34074 G15
PIN FUNCTIONS VFB1 (Pin 1):
Output Feedback. Receives the feedback volt- synchronized to an external oscillator applied to this pin age from the external resistive divider across the output. and pulse-skipping mode is automatically selected. Nominal voltage for this pin is 0.6V.
SW2 (Pin 7):
Regulator 2 Switch Node Connection to the
RUN1 (Pin 2):
Regulator 1 Enable. Forcing this pin to VIN Inductor. This pin swings from VIN to GND. enables regulator 1, while forcing it to GND causes regulator
POR (Pin 8):
Power-On Reset . This common-drain logic 1 to shut down. This pin must be driven; do not fl oat. output is pulled to GND when the output voltage is not
VIN (Pin 3):
Main Power Supply. Must be closely decoupled within ±8.5% of regulation and goes high after 29ms when to GND. both channels are within regulation.
SW1 (Pin 4):
Regulator 1 Switch Node Connection to the
RUN2 (Pin 9):
Regulator 2 Enable. Forcing this pin to VIN Inductor. This pin swings from VIN to GND. enables regulator 2, while forcing it to GND causes regulator 2 to shut down. This pin must be driven; do not fl oat.
GND (Pin 5):
Ground. This pin is not connected internally. Connect to PCB ground for shielding.
VFB2 (Pin 10):
Output Feedback. Receives the feedback voltage from the external resistive divider across the output.
MODE/SYNC (Pin 6):
Combination Mode Selection and Nominal voltage for this pin is 0.6V. Oscillator Synchronization. This pin controls the opera- tion of the device. When tied to VIN or GND, Burst Mode
Exposed Pad (GND) (Pin 11):
Power Ground. Connect to operation or pulse-skipping mode is selected, respectively. the (–) terminal of COUT, and (–) terminal of CIN. Must be Do not fl oat this pin. The oscillation frequency can be connected to electrical ground on PCB. 34074fa 5