LMX2433 datasheet(29/53 Pages) TI1

29 / 53 page

LMX2430, LMX2433, LMX2434

www.ti.com

SNAS187D – FEBRUARY 2003 – REVISED JANUARY 2016

Device Functional Modes (continued)

reference divider are held at their load point. This allows the reference oscillator, feedback divider, reference

divider, and prescaler circuitry to reach proper bias levels. After a finite delay, the feedback and reference

dividers are enabled and resume counting in close alignment (the maximum error is one prescaler cycle). The

MICROWIRE control register remains active and capable of loading and latching data while in power-down

mode.

9.4.1.1 Synchronous Power-Down Mode

In this mode, the power-down function is gated by the charge pump. When the device is configured for

synchronous power down, the device enters the power-down mode upon completion of the next charge-pump

pulse event.

9.4.1.2 Asynchronous Power-Down Mode

In the asynchronous power-down mode, the power-down function is NOT gated by the completion of a charge-

pump pulse event. When the device is configured for asynchronous power down, the part goes into power-down

mode immediately.

Table 7. Power-Down Modes

RF_CPT / IF_CPT

RF_PD /

EN PIN

OPERATING MODE

BIT

IF_PD BIT

X(1)

Asynchronous Power Down

PLL Active. Normal Operation

PLL Active. Charge-Pump Output in High-Impedance State

Synchronous Power Down

Asynchronous Power Down

(1)

X refers to a don’t care condition.

9.5 Programming

9.5.1 Microwire Interface

The 24-bit shift register is loaded through the MICROWIRE interface. The shift register consists of a 21-bit

DATA[20:0] FIELD and a 3-bit ADDRESS[2:0] FIELD as shown in Table 8. The ADDRESS FIELD is used to

decode the internal control register address. When LE transitions HIGH, DATA stored in the shift register is

loaded into one of 6 control registers depending on the state of the ADDRESS bits. The MSB of DATA is loaded

into the shift register first. The DATA FIELD assignments are shown in Control Register Content Map.

Table 8. Register Structure

MSB

LSB

DATA[20:0]

ADDRESS[2:0]

3 2

Submit Documentation Feedback

Product Folder Links: LMX2430 LMX2433 LMX2434

LMX2433 Datasheet(PDF) 29 Page - Texas Instruments

LMX2433 Datasheet(HTML) 29 Page - Texas Instruments

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

Datasheet Download

Link URL