_______________Detailed Description

The MAX1007 comprises several blocks for measuring

and controlling radio-frequency (RF) signals. The mea-

surement blocks, including power sense, antenna or

preamble-switched diversity, and the analog-to-digital

converter (ADC), allow the comparison of various RF

inputs. The control blocks, including four digital-to-ana-

log converters (DACs), digital outputs BANT and SDG,

and the serial interface, aid frequency tuning and allow

the optimization of transceiver gain under microproces-

sor control.

Power Sense

The power-sense circuit consists of a multiplexer (mux),

a programmable gain amplifier (PGA), a peak detector,

and a buffer. The circuit amplifies/attenuates the

demodulated RF waveform, peak-holds the signal, and

buffers the outputs to the ADC for power-sense mea-

surement.

The demodulation process with external circuitry for

one channel is shown in Figures 3a and 3b. This circuit

typically recovers the negative envelope of the RF

waveform. The 1.87V PSBIAS voltage and the 100µA

current source are both generated by the MAX1007.

Mobile-Radio Analog Controller

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7

CONTROL

SIGNALS

STATE

INTERNAL SIGNALS

ADCCTRL

PKWDW

1

≥ 7 CLOCKS

2

CLOCKS

ACTIVE ADC

ADC CONVERSION

RESET

SWITCH FOR PS

10 CLOCKS

1

10 CLOCKS

8 CLOCKS

8 CLOCKS

6 CLOCKS

1

B

C

A

Figure 1. RSSI/Power-Sense Control Signals

ANTENNA SELECT

(EXTERNALLY GENERATED)

STATE

RSSI

FIRST ANTENNA

SECOND ANTENNA

PSDWDW

PSDCTRL

BANT

NEW VALUE

INTERNAL RESET 1

INTERNAL RESET 2

OLD VALUE

PERIOD A

PERIOD B

1

8 CLOCKS

4

4

9 CLOCKS

D

COMPARE

Figure 2. Antenna-Diversity Control Signals