LTM4651 datasheet(20/54 Pages) AD

20 / 54 page

LTM4655

Rev. 0

For more information www.analog.com

CLKSET (F12): Clock Generator Frequency Setting

Resistor Input. Apply a resistor, RCLKSET, between

LDOOUT and CLKSET. The clock frequency of CLKOUT1

and CLKOUT2 is set by RCLKSET, according Equation 3.

f(CLKOUT1, CLKOUT2) = 10MHz•

10kΩ

RCLKSET(kΩ)

(3)

Resistor values between 32.2k and 400k are supported,

corresponding to oscillator frequency settings of 3MHz

to 250kHz, respectively. Minimize stray capacitance to

this pin.

CLKOUT1 (B2): Squarewave Output of Clock Generator for

Channel 1. 180° out-of-phase from CLKOUT2. Minimize

stray capacitance to this pin. Connect CLKOUT1 to

CLKIN1, if desired, to synchronize channel 1 to CLKOUT1.

If 0° phase interleaving is desired, connect CLKOUT1 to

both CLKIN1 and CLKIN2.

CLKOUT2 (B7, C12): Squarewave Output of Clock

Generator for Channel 2. 180° out-of-phase from

CLKOUT1. Minimize stray capacitance to these pins.

Connect CLKOUT2 (pin B7, only) to CLKIN2, if desired,

to synchronize channel 2 to CLKOUT2. If 0° phase inter-

leaving is desired, connect CLKOUT1 to both CLKIN1 and

CLKIN2.

To disable spread spectrum frequency modulation

(SFFM), connect CLKOUT2 (pin C12, only) to the MOD

pin (pin E12) with a short trace.

The CLKOUT2 pins at locations B7 and C12 are electri-

cally connected together by a signal trace internal to the

module. It is pinned out as described purely to facilitate

routing of short traces to CLKIN2 and MOD. CLKOUT2

should be routed with minimal trace lengths. Minimize

stray capacitance to these pins.

MOD (E12): Modulation Setting Input. This three-state

input selects among four modulation rate settings. The

MOD pin should be tied to GND for the fOUT/16 modulation

rate. Leaving the MOD pin open circuit selects the fOUT/32

modulation rate. The MOD pin should be electrically

connected to LDOOUT for the fOUT/64 modulation rate.

Electrically connecting CLKOUT2 (pin C12, only) to the

MOD pin (pin E12) turns the modulation off. Do not route

high speed digital logic or signals with fast edges near

MOD. Be advised that the fOUT/16, fOUT/32 and fOUT/64

modulation rates are not explicitly tested in factory ATE

to demonstrate their stated typical modulation rates; the

modulation off setting, however, is.

NC (J1–2, J11–12): No Connect Pins, i.e., Pins with No

Internal Connection. The NC pins predominantly serve to

provide improved mounting of the module to the board.

For drop-in compatibility of the LTM4651/LTM4653 into

either half of a LTM4655 layout, these NC are recom-

mended to be left electrically open circuit.

PIN FUNCTIONS

LTM4651 데이터시트(PDF) 20 Page - Analog Devices

LTM4651 데이터시트(HTML) 20 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

데이터시트 다운로드

링크 URL