AD6402

–5–

REV. 0

Table I. Power Management Functionality

PLL

PLL

PLL

TL1

CTL2

CTL3

BIAS

LOCK

DMOD

REF

REG

RX

VCO

MODE

0

0

0

–

–

–

OFF

OFF

–

–

SLEEP

0

0

1

–

–

–

OFF

ON

–

–

STANDBY

010ON

ON

OFF

ON

ON

OFF

ON

RXLOCK

1

X

0

ON

OFF

ON

ON

ON

ON

ON

RXDMOD

1

0

1

OFF

OFF

OFF

ON

ON

OFF

ON

TRANSMIT

111ON

ON

OFF

ON

ON

ON

ON

RXLOCKP

REF

RX

PLL DMOD

PLL BIAS

REF

REG

PLL LOCK

VCO

IFVCC1

IFVCC2

RSSI

DOUT

DFLIP

PLLOUT

PLLVCC

PLLGND

REXT

CFILT

REFSEL

FMMOD2

FMMOD1

MODOUT

TXOUTB

TXOUT

CTL1

CTL2

CTL3

VCOGND

VCO

SLREF

VREG

VBAT

IFGND

IFIN

COFF

REFIN

REG

CP

/2

CP

/3,/5

PD

Figure 2. Power Management Scheme

The AD6402 has six operating modes: SLEEP, STANDBY,

RXLOCK, RXDMOD, TRANSMIT and RXLOCKP. These

are summarized in Table I. The blocks referred to in Table I are

shown also in Figure 4. These modes are described as follows:

SLEEP:

The entire device is shut down.

STANDBY:

All functions except the regulator are shut down.

RXLOCK:

The device locks to a local reference clock using

the lock PLL. The lock charge pump and divid-

ers are powered up. The VCO is also powered up.

RXDMOD:

In this mode the lock charge pump and loop

dividers are shut down. The receive mixer, IF strip,

reference and demodulator are powered up.

TRANSMIT: This mode enables the VCO and transmit op

amp. The reference and regulator are also enabled.

RXLOCKP:

This mode may be used in a “prior to” timeslot,

i.e., the slot before the actual active receive

timeslot. In this mode, after lock has been

achieved in the RXLOCK mode, the receive

mixer, VCO and IF strip may then be indepen-

dently powered up from the demodulator loop.

This can result is power savings, since the de-

modulator may be powered down during the

IF VCO lock acquisition time.