LTM4607 datasheet(10/28 Pages) LINER

10 / 28 page

LTC3780

3780fe

PIN FUNCTIONS (SSOP/QFN)

VOSENSE (Pin 6/Pin 4): Error Ampliﬁer Feedback Input.

This pin connects the error ampliﬁer input to an external

resistor divider from VOUT.

SGND (Pin 7/Pin 5): Signal Ground. All small-signal com-

ponents and compensation components should connect

to this ground, which should be connected to PGND at a

single point.

RUN (Pin 8/Pin 6): Run Control Input. Forcing the RUN

pin below 1.5V causes the IC to shut down the switching

regulator circuitry. There is a 100k resistor between the RUN

pin and SGND in the IC. Do not apply >6V to this pin.

FCB (Pin 9/Pin 7): Forced Continuous Control Input. The

voltage applied to this pin sets the operating mode of the

controller. When the applied voltage is less than 0.8V, the

forced continuous current mode is active. When this pin

is allowed to ﬂoat, the Burst Mode operation is active in

boost operation and the skip-cycle mode is active in buck

operation. When the pin is tied to INTVCC, the constant

frequency discontinuous current mode is active in buck

or boost operation.

PLLFLTR (Pin 10/Pin 8): The phase-locked loop’s

lowpass ﬁlter is tied to this pin. Alternatively, this pin can

be driven with an AC or DC voltage source to vary the

frequency of the internal oscillator.

PLLIN (Pin 11/Pin 10): External Synchronization Input to

Phase Detector. This pin is internally terminated to SGND

with 50kΩ. The phase-locked loop will force the rising

bottom gate signal of the controller to be synchronized

with the rising edge of the PLLIN signal.

STBYMD (Pin 12/Pin 11): LDO Control Pin. Determines

whether the internal LDO remains active when the control-

ler is shut down. See Operation section for details. If the

STBYMD pin is pulled to ground, the SS pin is internally

pulled to ground, preventing start-up and thereby provid-

ing a single control pin for turning off the controller. To

keep the LDO active when RUN is low, for example to

power a “wake up” circuit which controls the state of the

RUN pin, bypass STBYMD to signal ground with a 0.1μF

capacitor, or use a resistor divider from VIN to keep the

pin within 2V to 5V.

BOOST2, BOOST1 (Pins 13, 24/Pins 14, 27): Boosted

Floating Driver Supply. The (+) terminal of the bootstrap

capacitor CAandCB(Figure11)connectshere.TheBOOST2

pin swings from a diode voltage below INTVCC up to VIN

+ INTVCC. The BOOST1 pin swings from a diode voltage

below INTVCC up to VOUT + INTVCC.

TG2, TG1 (Pins 14, 23/Pins 15, 26): Top Gate Drive. Drives

the top N-channel MOSFET with a voltage swing equal to

INTVCC superimposed on the switch node voltage SW.

SW2, SW1 (Pins 15, 22/Pins 17, 24): Switch Node. The (–)

terminal of the bootstrap capacitor CA and CB (Figure 11)

connects here. The SW2 pin swings from a Schottky diode

(external) voltage drop below ground up to VIN. The SW1

pin swings from a Schottky diode (external) voltage drop

below ground up to VOUT.

BG2, BG1 (Pins 16, 18/Pins 18, 20): Bottom Gate Drive.

Drives the gate of the bottom N-channel MOSFET between

ground and INTVCC.

PGND (Pin 17/Pin 19): Power Ground. Connect this pin

closely to the source of the bottom N-channel MOSFET, the

(–) terminal of CVCC and the (–) terminal of CIN (Figure 11).

INTVCC (Pin 19/Pin 21): Internal 6V Regulator Output. The

driver and control circuits are powered from this voltage.

Bypass this pin to ground with a minimum of 4.7μF low

ESR tantalum or ceramic capacitor.

EXTVCC (Pin 20/Pin 22): External VCC Input. When EXTVCC

exceeds 5.7V, an internal switch connects this pin to INTVCC

and shuts down the internal regulator so that the controller

and gate drive power is drawn from EXTVCC. Do not exceed

7V at this pin and ensure that EXTVCC < VIN.

VIN (Pin 21/Pin 23): Main Input Supply. Bypass this pin

to SGND with an RC ﬁlter (1Ω, 0.1μF).

Exposed Pad (Pin 33, QFN Only): This pin is SGND and

must be soldered to PCB ground.

LTM4607 数据表(PDF) 10 Page - Linear Technology

LTM4607 数据表(HTML) 10 Page - Linear Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28

数据表下载