LTM8045 datasheet(19/54 Pages) AD

19 / 54 page

LTM4655

Rev. 0

For more information www.analog.com

IMON2a (C7): Channel 2 Power Inductor Current Analog

Indicator Pin and Current Limit Programming Pin. In

positive-VOUT step-down applications, only, the current

flowing out of this pin is equal to 1/40,000 of the average

channel 2 power inductor current. Optionally apply a par-

allel resistor-capacitor network to this pin and terminate

it to SVOUT2– in order to construct a voltage (VIMON2a–

SVOUT2–) that is proportional to channel 2’s power induc-

tor current.

IMON2a can be connected to IMON2b if the default resis-

tor capacitor termination network provided by IMON2b is

desired. If this analog indicator feature is not desired—

or, in negative-VOUT– buck-boost applications: connect

IMON2a to SVOUT2–.

If IMON2a–SVOUT2– exceeds a trip threshold of approxi-

mately 2V, an IMON2 control loop servos channel 2

power inductor current accordingly and thus regulates

IMON2a–SVOUT2– at 2V. In this manner, the current limit

inception threshold of channel 2 can be configured. (See

the Applications Information section.)

IMON2b (C6): Channel 2 Power Inductor Analog Indicator

Current Default Termination R-C Network. A 10k resis-

tor in parallel with a 10nF capacitor and terminating to

SVOUT2– connect to this pin. Connect IMON2b to IMON2a

to achieve default power inductor analog indicator current

characteristics: 1V (with respect to SVOUT2–) at full-scale

(4A) load current in positive-VOUT, noninverting step-

down applications. (See IMON2a.) If unused, IMON2b

can be left open circuit or connected to SVOUT2–.

VINREG1 (D3): Channel 1 Input Voltage Regulation

Programming Pin. Optionally connect this pin to the

midpoint node formed by a resistor divider between VD1

and VOUT1–. If VINREG1–SVOUT1– falls below approxi-

mately 2V, a VINREG1 control loop servos the power

inductor current accordingly and thus regulates VINREG1

at 2V with respect to SVOUT1–. (See the Applications

Information section.)

If this input voltage regulation feature is not desired on

channel 1, connect VINREG1 to INTVCC1.

VINREG2 (D8): Channel 2 Input Voltage Regulation

Programming Pin. Optionally connect this pin to the mid-

point node formed by a resistor divider between VD2 and

VOUT2–. If VINREG2–SVOUT2– falls below approximately

2V, a VINREG2 control loop servos the power inductor

current accordingly and thus regulates VINREG2 at 2V

with respect to SVOUT2–. (See the Applications Information

section.)

If this input voltage regulation feature is not desired on

channel 2, connect VINREG2 to INTVCC2.

TEMP+ (J6): Temperature Sensor, Positive Input. Emitter

of a 2N3906-genre PNP bipolar junction transistor (BJT).

Optionally interface to temperature monitoring circuitry

such as LTC®2997, LTC2990, LTC2974 or LTC2975.

Otherwise leave electrically open.

TEMP– (J7): Temperature Sensor, Negative Input. Collector

and base of a 2N3906-genre PNP bipolar junction tran-

sistor (BJT). Optionally interface to temperature moni-

toring circuitry such as LTC2997, LTC2990, LTC2974 or

LTC2975. Otherwise leave electrically open.

SW1 (H4): Switching Node of Channel 1 Switching

Converter Stage. Used for test purposes. May be routed

a short distance with a thin trace to a local test point to

monitor switching action of the converter, if desired, but

do not route near any sensitive signals; otherwise, leave

electrically open circuit.

SW2 (H9): Switching Node of Channel 2 Switching

Converter Stage. Used for test purposes. May be routed

a short distance with a thin trace to a local test point to

monitor switching action of the converter, if desired, but

do not route near any sensitive signals; otherwise, leave

electrically open circuit.

LDOOUT (G12): Output of the LTM4655’s GND Referenced

5V-Fixed LDO. No bypass capacitance is needed. Powers

the clock generator internal to the LTM4655. Can deliver

up to 25mA of current.

PIN FUNCTIONS

LTM8045 Datasheet(PDF) 19 Page - Analog Devices

LTM8045 Datasheet(HTML) 19 Page - Analog Devices

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 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54

Datasheet Download

Link URL