Datasheet LTC3834-1 (Analog Devices) - 7
| Hersteller | Analog Devices |
| Beschreibung | 30μA IQ Synchronous Step-Down Controller |
| Seiten / Seite | 28 / 7 — TYPICAL PERFOR A CE CHARACTERISTICS TA = 25ºC, unless otherwise noted. … |
| Dateiformat / Größe | PDF / 300 Kb |
| Dokumentensprache | Englisch |
TYPICAL PERFOR A CE CHARACTERISTICS TA = 25ºC, unless otherwise noted. INTVCC vs Load Current
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LTC3834-1
W U TYPICAL PERFOR A CE CHARACTERISTICS TA = 25ºC, unless otherwise noted. INTVCC vs Load Current Shutdown Current vs Temperature
5.3 7 5.2 V 6 IN = 12V μA) 5.1 5 5.0 4 VOLTAGE (V) 4.9 3 CC INTV 4.8 2 SHUTDOWN CURRENT ( 4.7 1 4.6 0 0 10 20 30 40 50 60 –45 –30 –15 0 15 30 45 60 75 90 LOAD CURRENT (mA) TEMPERATURE (°C) 38341 G26 38341 G27
U U U PI FU CTIO S (DHC Package/GN Package) PLLLPF (Pin 1/Pin 1):
The phase-locked loop’s lowpass
BG (Pin 7/Pin 7):
High Current Gate Drive for Bottom filter is tied to this pin when synchronizing to an external (Synchronous) N-Channel MOSFET. Voltage swing at this clock. Alternatively, tie this pin to GND, INTVCC or leave pin is from ground to INTVCC. floating to select 250kHz, 530kHz or 400kHz switching
INTV
frequency.
CC (Pin 8/Pin 8):
Output of the Internal Linear Low Dropout Regulator. The driver and control circuits are
ITH (Pin 2/Pin 2):
Error Amplifier Outputs and Switching powered from this voltage source. Must be decoupled to Regulator Compensation Points. The current comparator power ground with a minimum of 4.7μF tantalum or trip point increases with this control voltage. ceramic capacitor.
TRACK/SS (Pin 3/Pin 3):
External Tracking and Soft-
VIN (Pin 9/Pin 9):
Main Supply Pin. A bypass capacitor Start Input. The LTC3834-1 regulates the VFB voltage should be tied between this pin and the signal ground pin. to the smaller of 0.8V or the voltage on the TRACK/ SS pin. A internal 1μA pull-up current source is connected
SW (Pin 10/Pin 10):
Switch Node Connections to Induc- to this pin. A capacitor to ground at this pin sets the tor. Voltage swing at this pin is from a Schottky diode ramp time to final regulated output voltage. Alternatively, (external) voltage drop below ground to VIN. a resistor divider on another voltage supply connected
TG (Pin 11/Pin 11):
High Current Gate Drive for Top N- to this pin allows the LTC3834-1 output to track the Channel MOSFET. These are the outputs of floating driv- other supply during startup. ers with a voltage swing equal to INTVCC – 0.5V superim-
V
posed on the switch node voltage SW.
FB (Pin 4/Pin 4):
Receives the remotely sensed feed- back voltage from an external resistive divider across
BOOST (Pin 12/Pin 12):
Bootstrapped Supply to the Top the output. Side Floating Driver. A capacitor is connected between the
SGND (Pin 5/Pin 5):
Small Signal Ground. Must be routed BOOST and SW pins and a Schottky diode is tied between separately from high current grounds to the common (–) the BOOST and INTVCC pins. Voltage swing at the BOOST terminals of the input pin is from INTV capacitor. CC to (VIN + INTVCC).
PGND (Pin 6/Pin 6):
Driver Power Ground. Connects to
RUN (Pin 13/Pin 13):
Digital Run Control Input for Con- the source of bottom (synchronous) N-channel MOSFET, troller. Forcing this pin below 0.7V shuts down all control- anode of the Schottky rectifier and the (–) terminal of CIN. 38341f 7
W U TYPICAL PERFOR A CE CHARACTERISTICS TA = 25ºC, unless otherwise noted. INTVCC vs Load Current Shutdown Current vs Temperature
5.3 7 5.2 V 6 IN = 12V μA) 5.1 5 5.0 4 VOLTAGE (V) 4.9 3 CC INTV 4.8 2 SHUTDOWN CURRENT ( 4.7 1 4.6 0 0 10 20 30 40 50 60 –45 –30 –15 0 15 30 45 60 75 90 LOAD CURRENT (mA) TEMPERATURE (°C) 38341 G26 38341 G27
U U U PI FU CTIO S (DHC Package/GN Package) PLLLPF (Pin 1/Pin 1):
The phase-locked loop’s lowpass
BG (Pin 7/Pin 7):
High Current Gate Drive for Bottom filter is tied to this pin when synchronizing to an external (Synchronous) N-Channel MOSFET. Voltage swing at this clock. Alternatively, tie this pin to GND, INTVCC or leave pin is from ground to INTVCC. floating to select 250kHz, 530kHz or 400kHz switching
INTV
frequency.
CC (Pin 8/Pin 8):
Output of the Internal Linear Low Dropout Regulator. The driver and control circuits are
ITH (Pin 2/Pin 2):
Error Amplifier Outputs and Switching powered from this voltage source. Must be decoupled to Regulator Compensation Points. The current comparator power ground with a minimum of 4.7μF tantalum or trip point increases with this control voltage. ceramic capacitor.
TRACK/SS (Pin 3/Pin 3):
External Tracking and Soft-
VIN (Pin 9/Pin 9):
Main Supply Pin. A bypass capacitor Start Input. The LTC3834-1 regulates the VFB voltage should be tied between this pin and the signal ground pin. to the smaller of 0.8V or the voltage on the TRACK/ SS pin. A internal 1μA pull-up current source is connected
SW (Pin 10/Pin 10):
Switch Node Connections to Induc- to this pin. A capacitor to ground at this pin sets the tor. Voltage swing at this pin is from a Schottky diode ramp time to final regulated output voltage. Alternatively, (external) voltage drop below ground to VIN. a resistor divider on another voltage supply connected
TG (Pin 11/Pin 11):
High Current Gate Drive for Top N- to this pin allows the LTC3834-1 output to track the Channel MOSFET. These are the outputs of floating driv- other supply during startup. ers with a voltage swing equal to INTVCC – 0.5V superim-
V
posed on the switch node voltage SW.
FB (Pin 4/Pin 4):
Receives the remotely sensed feed- back voltage from an external resistive divider across
BOOST (Pin 12/Pin 12):
Bootstrapped Supply to the Top the output. Side Floating Driver. A capacitor is connected between the
SGND (Pin 5/Pin 5):
Small Signal Ground. Must be routed BOOST and SW pins and a Schottky diode is tied between separately from high current grounds to the common (–) the BOOST and INTVCC pins. Voltage swing at the BOOST terminals of the input pin is from INTV capacitor. CC to (VIN + INTVCC).
PGND (Pin 6/Pin 6):
Driver Power Ground. Connects to
RUN (Pin 13/Pin 13):
Digital Run Control Input for Con- the source of bottom (synchronous) N-channel MOSFET, troller. Forcing this pin below 0.7V shuts down all control- anode of the Schottky rectifier and the (–) terminal of CIN. 38341f 7