Philips UAA2068AHL Datasheet

INTEGRATED CIRCUITS

DATA SH EET

UAA2068AHL

Transmit chain and synthesizer with integrated VCO for DECT

Product speciﬁcation File under Integrated Circuits, IC17

1999 Jun 04

Philips Semiconductors Product speciﬁcation

Transmit chain and synthesizer with integrated VCO for DECT

FEATURES

• Economical integrated solution for frequency generation in DECT cordless telephones

• Integrated low phase noise 950 MHz VCO with frequency doubler

• Local Oscillator (LO) drive (−14 dBm) for RF mixer circuit

• Dedicated DECT PLL synthesizer

• 3-line serial interface bus

• 3 dBm output preamplifier with an integrated switch

• Low current consumption from 3 V supply

• Compatible with Philips Semiconductors ABC baseband

chip (PCD509x series).

APPLICATIONS

• 1880 to 1920 MHz DECT cordless telephones.

GENERAL DESCRIPTION

The UAA2068AHL BiCMOS device integrates a 950 MHz VCO, a frequency doubler, main and reference dividers and a phase comparator, to implement a phase-locked loop for DECT channel frequencies. The 1.9 GHz signal is buffered and switched, in TX mode, to drive the transmit power amplifier (CGY20xx series) or, in RX mode, to be used as an LO signal for the receiver mixer IC (UAA3540TS).

UAA2068AHL

The reference divider ratio is fixed at 16. Outputs of the main and reference dividers drive a phase comparator where a charge pump produces phase error current pulses for integration in an external loop filter. Only a passive loop filter is necessary. The charge-pump current (phase comparator gain) is set by an external resistor (R R

SET

The VCO is powered from an internally regulated voltage source and includes internal varicap diodes. Its tuning range is wider than the required band to allow for production spreads. In a Time Division Multiple Access (TDMA) system such as DECT, the VCO and the synthesizer are switched on one slot before the required one to lock the VCO to the required channel frequency. Just before the required slot, the synthesizer is switched off, allowing open-loop modulation of the VCO during transmission. When opening the loop, the frequency pulling (due to switching off the synthesizer) can be maintained within the DECT specification.

The device is designed to operate from 3 NiCd cells in pocket phones, with low current and nominal 3.6 V supplies. Separate power and ground pins are provided to the different parts of the circuit. The ground leads should be short-circuited externally to prevent large currents flowing across the die and thus causing damage. All supply pins (VCC) must also be at the same potential, except V other supply pins (e.g. VCC= 3 V and V wider VCO control voltage range).

which can be equal to or greater than the

CC(CP)

) at pin

SET

= 5 V for

The synthesizer’s main divider is driven by the frequency doubler output in the range from 1880 to 1920 MHz and programmed via a 3-wire serial bus.

ORDERING INFORMATION

TYPE NUMBER

NAME DESCRIPTION VERSION

UAA2068AHL LQFP32 plastic low proﬁle quad ﬂat package; 32 leads; body 5 × 5 × 1.4 mm SOT401-1

1999 Jun 04 2

PACKAGE

Philips Semiconductors Product speciﬁcation

Transmit chain and synthesizer with

UAA2068AHL

integrated VCO for DECT

QUICK REFERENCE DATA

= 3.6 V; V

given are not tested.

SYMBOL PARAMETER CONDITIONS MIN. TYP. MAX. UNIT

CC(CP)

CC(SYA)

CC(SYD)

CC(VCO)

CC(BUF)

CC(DBL)

CC(AMP)

CC(pd)

o(RF)

xtal

amb

CC(CP)

= 3.6 V; T

=25°C; unless otherwise speciﬁed. Characteristics for which only a typical value is

amb

supply voltage 3.0 3.6 5.2 V charge-pump supply voltage V

CC(CP)

≥ V

3.0 3.6 5.2 V

synthesizer supply current S_EN = 1 − 9.5 14 mA

VCO and buffer parts supply current VCO_ON = 1 − 9.5 14 mA

doubler supply current in RX mode − 14.4 19 mA

in TX mode − 10 14 mA

TX preampliﬁer supply current in RX mode − 050µA

in TX mode − 24 32 mA total supply current in Power-down mode − 550µA RF output frequency 1880 − 1920 MHz crystal reference input frequency − 13.824 − MHz phase comparator frequency − 864 − kHz operating ambient temperature −10 − +60 °C

1999 Jun 04 3

Philips Semiconductors Product speciﬁcation

Transmit chain and synthesizer with integrated VCO for DECT

BLOCK DIAGRAM

handbook, full pagewidth

R_OFF

AMPGND

CC(SYD)

CC(SYA)

TXA TXB

LOA LOB

26 29 28

12 13

2 5

CC(AMP)

30 15 11 16 17 24 21 20

PREAMP

CC(DBL)

BUFFER

3-LINE BUS

1 31 4 3 6 10 7

T_EN

SWITCH

MAIN DIVIDER

REFERENCE DIVIDER

CC(DBL)

DOUBLER

CC(BUF)

BUFFER

UAA2068AHL

PHASE

COMPARATOR

CC(VCO)

REG

VCO

UAA2068AHL

VCOB

VCOA

23 18

25 22 19 14

CHARGE

PUMP

TUNE

MOD

VCO_ON VCGND VCOGND DBLGND

CC(CP)

S_EN

DATA

CLK

XTAL

SYDGND

SYAGND

Fig.1 Block diagram.

1999 Jun 04 4

SET

CPGND

SET

FCA071

Philips Semiconductors Product speciﬁcation

Transmit chain and synthesizer with integrated VCO for DECT

PINNING

SYMBOL PIN DESCRIPTION

DATA 1 3-wire programming bus data input V

CC(SYD)

SYDGND 3 synthesizer CMOS divider ground XTAL 4 reference frequency input V

CC(SYA)

SYAGND 6 synthesizer prescaler ground CPGND 7 charge-pump ground CP 8 charge-pump output signal V

CC(CP)

SET

CC(DBL)

LOA 12 local oscillator output A LOB 13 local oscillator output B DBLGND 14 doubler ground T_EN 15 transmit enable signal input V

CC(BUF)

CC(VCO)

MOD

VCOGND 19 VCO ground; note 1 VCOA 20 VCO inductor connection A VCOB 21 VCO inductor connection B VCGND 22 internal varicap ground; note 1 V

TUNE

REG

VCO_ON 25 VCO power-on control input; note 2 R_OFF 26 power-on control for RX LO buffer/TX preampliﬁer; note 3 AMPGND 27 transmit ampliﬁer ground TXB 28 transmit ampliﬁer output B TXA 29 transmit ampliﬁer output A V

CC(AMP)

CLK 31 3-wire programming bus clock input S_EN 32 synthesizer enable signal input

2 synthesizer CMOS divider positive supply voltage

5 synthesizer prescaler positive supply voltage

9 charge-pump positive supply voltage 10 charge-pump current setting input 11 doubler positive supply voltage

16 VCO isolation buffer positive supply voltage 17 VCO positive supply voltage 18 transmit modulation input

23 VCO tuning input 24 VCO regulator output

30 transmit ampliﬁer positive supply voltage

UAA2068AHL

Notes

1. Pins 19 and 22 are internally short-circuited.

2. Use with S_PWR on ABC baseband chip.

3. Use with R_PWR on ABC baseband chip.

1999 Jun 04 5

Philips Semiconductors Product speciﬁcation

Transmit chain and synthesizer with integrated VCO for DECT

handbook, full pagewidth

CLK

S_EN

DATA

XTAL

2 3 4 5 6 7 8

SET

CC(CP)

CC(SYD)

SYDGND

CC(SYA)

SYAGND

CPGND

CC(AMP)

V 30

TXA 29

TXB 28

UAA2068AHL

LOB

LOA

CC(DBL)

R_OFF

AMPGND 27

T_EN

DBLGND

VCO_ON

CC(BUF)

24 23 22 21 20 19 18 17

FCA070

REG

TUNE

VCGND VCOB VCOA VCOGND V

MOD

CC(VCO)

UAA2068AHL

Fig.2 Pin configuration.

FUNCTIONAL DESCRIPTION Transmit chain

BUFFER AND FREQUENCY DOUBLER

VCO, The VCO operates at a nominal centre frequency of

950 MHz. The VCO is fully integrated apart from two inductors which complete the resonator network. The VCO operates from an on-chip regulated power supply (V

REG

which minimizes frequency disturbances due to variations in supply voltage. The buffered VCO signal is fed into a frequency doubler. The large difference between the transmitted and VCO frequencies reduces transmitter oscillator coupling problems.

The output of the doubler is used to drive the synthesizer main divider and can also be switched to either the TX preamplifier or the RX LO output buffer. The high isolation obtained from the VCO buffer and the frequency doubler ensures that very small frequency changes occur when turning on the TX preamplifier or the RX LO output buffer. In TX mode, the oscillator can be directly modulated with GMSK filtered data at pin V

MOD

RF SWITCH The RF switch passes the doubled VCO signal to either

the TX preamplifier (when T_EN is HIGH) or to the RX LO buffer (when T_EN is LOW). In TX mode, the difference in the RF power levels, observed at the TX output when T_EN is switched from LOW-to-HIGH, is typically 40 dB.

PREAMPLIFIER

The TX preamplifier amplifies the RF signal up to a level of 3 dBm which is suitable for use with Philips Semiconductors DECT power amplifiers such as the CGY20xx series. It is powered-up when both R_OFF and VCO_ON are HIGH.

RX LO

BUFFER

The RX LO buffer outputs the frequency doubled VCO signal at a level of −14 dBm. This signal can then be used as the local oscillator drive for the receive mixers of devices such as the UAA3540TS. The buffer is powered-up when R_OFF is LOW and VCO_ON is HIGH.

1999 Jun 04 6

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