ADRF6750

Rev. A | Page 9 of

40

Pin No.

Mnemonic

Description

27

CS

Chip Select, CMOS Input. When CS is high, the data stored in the shift registers is loaded into one of

the slave address is 0x40.

29

SDI/SDA

tional port.

30

CLK/SCL

This input is a high impedance CMOS input.

28

SDO

Serial Data Output for SPI Port. Register states can be read back on the SDO data output line.

17

REFIN

Reference Input. This high impedance CMOS input should be ac-coupled.

18

REFIN

Reference Input Bar. This pin should be either grounded or ac-coupled to ground.

48

RFOUT

RF Output. Single-ended, 50 Ω, internally biased RF output. This pin must be ac-coupled to the

load. Nominal output power is −1.6 dBm for a single sideband baseband drive of 0.9 V p-p differ-

ential on the I and Q inputs (attenuation = minimum).

45

TXDIS

Output Disable. This pin can be used to disable the RF output. Connect to high logic level to disable

the output. Connect to low logic level for normal operation.

25, 26

LOMONP,

LOMONN

Differential Monitor Outputs. These pins provide a replica of the internal local oscillator frequency

(1× LO) at four different power levels: −6 dBm, −12 dBm, −18 dBm, and −24 dBm, approximately.

These open-collector outputs must be terminated with external resistors to REGOUT. These outputs

can be disabled through serial port programming and should be tied to REGOUT if not used.

22, 23

TESTLO,

TESTLO

Differential Test Inputs. These inputs provide an option for an external 2× LO to drive the modulator.

This option can be selected by serial port programming. These inputs must be externally dc-biased and

should be grounded if not used.

10, 8

LF2, LF3

No connect pins.

44

LDET

Lock Detect. This output pin indicates the state of the PLL: a high level indicates a locked condition,

whereas a low level indicates a loss of lock condition.

43

MUXOUT

Muxout. This output is a test output for diagnostic use only. It should be left unconnected by the

customer.

Exposed Paddle

EP

Exposed Paddle. Connect to ground plane via a low impedance path.