Texas Instruments TRF3520PFB Datasheet

GSM RF MODULATOR/DRIVER AMPLIFIER

SLWS060A – MAY 1998

Modulation and Upconversion from I/Q Baseband to RF on Single Chip

Designed for GSM Portable Cellular Telephones

Internal VCO and SSB Mixer for Transmit Carrier Generation

Internal RF Filter for Minimal External Parts

description

The TRF3520 radio frequency (RF) modulator/amplifier is a single-chip RF integrated circuit (IC) suitable for 900-MHz wireless global system for mobile communications (GSM) applications. It combines a direct conversion RF in-phase/quadrature-phase (I/Q) modulator, a single-sideband suppressed carried (SSB) mixer , an RF filter, a power amplifier (PA) driver, a buffered voltage-controlled oscillator (VCO), and a serial interface into one small package. Very few external components are required. During idle operation, the individual functional elements may be selectively placed in standby mode for minimum power consumption.

PFB PACKAGE

(TOP VIEW)

Power Amplifier Driver

Independent Power-Up/-Down Functions

3.75-V Operation

Low Current Consumption

Serial Data Interface

48-Pin Plastic Quad Flatpack (PFB)

TRF3520

TXO_

47 46 45 44 4348 42

TXO_TNK2 TXO_TNK1

TXO_GND

PSUB

DRV_GND DRV_OUT– DRV_OUT+

DRV_GND

NC NC NC

1 2 3 4 5 6 7 8 9 10 11 12

14 15

DRV_GND

NC – No internal connection

TXO_GND

TXO_SYNNCDB2_GND

17 18 19 20

VBG_IN

DRV_

DRV_GND

DIG_

DB2_OUT

DB2_

40 39 3841

I+

VBG_OUT

DIG_CLK

DIG_STR

DIG_DAT

22 23 24

I–

Q+

MOD_GND

DIG_GND

TXM_V

TXM_GND

TXM_LO+

34 33

TXM_LO–

TXM_GND TXM_GND

PH2

PH1

MOD_GND

MOD_V

MOD_GND

Q–

These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the gates.

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters.

POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

TRF3520 GSM RF MODULATOR/DRIVER AMPLIFIER

SLWS060A – MAY 1998

functional block diagram

I + I –

Q + Q –

TXM_LO+ TXM_LO–

20 21

23 24

External

Tank

34 33

TXO_TNK2

Transmit

TXO_TNK1

90°

IF VCO

0°

I/Q Modulator

Buffer

Limiter

÷ 2

∑

Band-Pass Filter (BPF)

Buffer

Low-Pass

Filter (LPF)

Power

Amplifier

Driver

To SYNTH (TXO_SYN)

+ –

Divide

(DB2_OUT)

DRV_OUT+ 11

DRV_OUT– 10

Single-Sideband Transmit Mixer

Buffer

-by-Two

Output

To External

Band

-Pass Filter,

Power Amplifier,

and Duplexer

Serial Interface

41 40 39 38 37

DIG_V

DIG_CLK

DIG_DAT

DIG_STR

DIG_GND

transmit IF VCO

The transmit intermediate frequency (IF) VCO generates a CW signal in the 200-MHz range. The IF VCO frequency is controlled by applying voltage to the required external tank varactors. Through on-chip buffers, the transmit IF VCO output is sent to the SSB transmit mixer and divide-by-two functional blocks, as well as to an external synthesizer where the transmit IF VCO frequency is controlled and phase locked. The error signal generated by the synthesizer is sent to the transmit IF VCO varactors’ tuning port, completing the phase-locked loop (PLL) function. The VCO is characterized for operation in the 74-MHz to 494-MHz range.

divide-by-two

This functional block halves the IF VCO frequency and provides a buffered amplitude-limited and low-pass filtered signal, which can become the LO signal for the TRF1020 GSM Receiver IC second down-conversion stage.

single-sideband transmit mixer (SSB Tx)

The SSB Tx mixer combines an external LO signal with the on-chip transmit IF VCO and performs a down-conversion function. The SSB Tx mixer suppresses the undesired upper sideband signal that is typically generated under the normal mixing process. An internal band-pass filter at the SSB Tx mixer output further reduces the undesired sideband and any spurious signals. This function eliminates the use of any external filtering. The LO is characterized for operation in the 990-MHz to 1400-MHz range.

I/Q modulator

The modulator provides direct I/Q modulation from baseband to RF . The differential baseband I/Q input signals also provide DC bias to the modulator. A nominal DC voltage of 1.35 V at the I and Q ports is required. Other types of complex I/Q modulations are possible with the TRF3520, but the device is optimized to meet GSM requirements.

POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

GSM RF MODULATOR/DRIVER AMPLIFIER

SLWS060A – MAY 1998

power amplifier driver output

The I/Q modulator output is fed to the power amplifier driver, which is a high-gain, low-distortion, fixed gain amplifier. Its dif ferential output can be converted to single-ended by a simple LC impedance-matching network and a 4:1 balun.

serial control interface

The serial control interface provides power-up and power-down capabilities for each of the functional blocks described in the previous paragraphs.

The TRF3520 device register is manipulated using a synchronous serial data port. The timing relationships are defined in Figure 1. One 17-bit word is clocked into a temporary holding register with the least significant bit clocked first. The operation register is loaded with the new data residing in the temporary registers using the rising edge of the strobe input.

The format of the control word is described in Table 1. Bits zero through two are reserved for future use. Bits three through seven are power conservation bits. Bits eight through 16 are reserved.

Table 1. Control Word Bit Assignments

BIT FUNCTION FUNCTIONAL IF

0 Reserved – 1 Reserved – 2 Reserved – 3 Transmit oscillator and buffer amplifiers 1 4 Transmit mixer, LO buffer amplifier 1 5 Modulator 1 6 PA driver amplifier 1 7 Divide-by-two and limiter 1 8 Reserved –

9 Reserved – 10 Reserved – 11 Reserved – 12 Reserved – 13 Reserved – 14 Reserved – 15 Reserved – 16 Reserved –

TRF3520

POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

TRF3520

I/O

DESCRIPTION

GSM RF MODULATOR/DRIVER AMPLIFIER

SLWS060A – MAY 1998

Terminal Functions

TERMINAL

NAME NO.

DB2_GND 44 – Divide-by-two circuitry ground DB2_OUT 43 O Divide-by-two frequency output DB2_V

DIG_CLK 40 I Digital clock input DIG_DAT 38 I Digital serial data input DIG_GND 37 – Digital ground DIG_STR 39 I Data strobe DIG_V

DRV_GND 9, 12, 13, 15 PA driver ground DRV_OUT+ 11 O PA driver noninverting output DRV_OUT– 10 O PA driver inverting output DRV_V

MOD_GND 22, 25, 27 Modulator ground I+ 20 I Noninverting in-phase input I– 21 I Inverting in-phase input Q+ 23 I Noninverting quadrature input Q– 24 I Inverting quadrature input MOD_V

NC 4, 5, 6, 8, 16,18, 30, 45 No internal connection PSUB 7 TXO_GND 3, 47 – Transmit VCO ground TXO_SYN 46 O Buffered transmit VCO output TXO_TNK1 2 – Transmit VCO tank connection 1 TXO_TNK2 1 – Transmit VCO tank connection 2 TXO_V

CC TXM_GND 31 – Transmit mixer ground TXM_GND 32 – Transmit mixer ground TXM_GND 35 – Transmit mixer ground TXM_LO+ 34 I Transmit mixer LO noninverting input TXM_LO– 33 I Transmit mixer LO inverting input TXM_V

CC PH1 28 – Phase adjustment resistor 1

PH2 29 – Phase adjustment resistor 2 VBG_IN 17 Band gap input VBG_OUT 19 Band gap output

42 – Divide-by-two circuitry bias supply

41 – Digital supply

14 – PA driver bias supply

26 – Modulator supply

48 – Transmit VCO supply

36 – Transmit mixer supply

POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

TRF3520

GSM RF MODULATOR/DRIVER AMPLIFIER

SLWS060A – MAY 1998

absolute maximum ratings over operating free-air temperature range (unless otherwise noted)

Supply voltage range: V

Input voltage to any other pin: VIN –0.3 V to (VCC + 0.3) V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Power dissipation, T Maximum operating junction temperature: T

= 25°C, 48-pin PQFP 600 mW. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Jmax

Operating ambient temperature range –40°C to 85 °C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Storage temperature range –65°C to 150 °C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

†

Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.

–0.3 V to 5.5 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

recommended operating conditions

MIN MAX UNIT

HIgh-level input voltage, V Low-level input voltage, V Supply voltage, V Operating free-air temperature,T

typical power consumption at 3.75 V (continuous operation)

MODULE OPERATING CURRENT STANDBY CURRENT OPERATING POWER STANDBY POWER

Transmit oscillator 8 mA <10 µA 30 mW <38 µW Transmit mixer (SSBM) 50 mA <10 µA 188 mW <38 µW Modulator 18 mA PA driver amplifier 45 mA <10 µA 169 mW <38 µW Divide-by-two + LPF 10 mA <10 µA 38 mW <38 µW Control logic 50 µA Total 131 mA <50 µA 492 mW <152 µW

2.0 V

–0.3 0.8 V

3.6 3.9 V

–40 85 °C

†

POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

TRF3520

DC current

GSM RF MODULATOR/DRIVER AMPLIFIER

SLWS060A – MAY 1998

electrical characteristics over recommended operating free-air temperature range (unless otherwise noted)

transmit IF VCO VCC = 3.75 V, TA = 25°C, ZO = 100 Ω (unless otherwise noted)

PARAMETER

Frequency range 141 194 247 MHz Output power (See Note 1) Z Phase noise 200-kHz offset –110 dBc/Hz

Power-up time (See Note 2) 10 µs Power-down time 10 µs

NOTES: 1. Measured at buffer output pin labeled TXO_SYN

2. Includes oscillator starting time. This time is measured starting at strobe transition to high; there is additional time after a reset, i.e., applying VCC to the circuit.

TEST

CONDITIONS

= 100 Ω –20 –15 dBm

load

Active mode 8 mA Standby mode 10 µA

MIN TYP MAX UNIT

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