ML2751

5

January, 2000

PRELIMINARY

PRELIMINARY DATASHEET

PIN DESCRIPTIONS (continued)

Pin #

Signal Name

I/O

Description

PIN Diode Driver Section

12

PIN

O (analog)

This output is a low impedance voltage source that switches between

VCC and GND to drive an external PIN diode switch. This totem pole

output is tri-stated when FEEN = 0. When active it pulls either to VCC

(if PAON = 1) or to GND (if PAON = 0), and has a nominal output

impedance of 50

W when sourcing and 120W when sinking

13

PINB

O (analog)

This output is a low impedance voltage source that switches between

VCC and GND to drive an external PIN diode switch. This totem pole

output is tri-stated when FEEN = 0. When active it pulls either to VCC

(if PAON = 0) or to GND (if PAON = 1) , and has a nominal output

impedance of 50

W when sourcing and 120W when sinking. PINB is the

complement of PIN, providing a bipolar drive for PIN diodes from a

single power rail

Control and Interface

1

PAON

I (CMOS)

Power Amplifier on pin. The PA is active when PAON = 1, and the LNA

is active when PAON = 0. Rising and falling edges of this signal

initiate a controlled ramp of the PA bias circuits to eliminate AM

generated sidebands on the transmitter output. The PIN diode drivers

are synchronized with PAON (see Figure 3). When the ML2751 is in

standby mode this pin has no effect

2

FEEN

I (CMOS)

Front-end enable. FEEN is the master power down pin. When FEEN = 0

the ML2751 is in standby mode. When FEEN = 1 either the PA or the

LNA is enabled (determined by the state of PAON). See Figure 3

Power & Ground

15

VCC

Power

Positive power supply for the LNA, the first stages of the PA, the PIN

diode drivers, and the control logic. Care should be exercised in PCB

layout to minimize the trace length, and the inductance and resistance

both in the connection to the capacitor and from the capacitor to

ground

4

GND

Ground

6

GND

Ground

7

GND

Ground

8

GND

Ground

14

GND

Ground

16

GND

Ground

17

GND

Ground

19

GND

Ground

20

GND

Ground