National Semiconductor LMV248 Technical data

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LMV248 Dual Band GSM Power Controller

September 2001

General Description

The LMV248 RF power amplifier controller allows simple implementation of transmit power control loops in GSM and DCS/PCS and mobile phones. The LMV248 supports, GaAs HBT and bipolar RF power amplifiers. The device operates from a single supply of 2.5V to 5V. The LMV248 includes an error amplifier with an input summing network, input and output band switches, input filters, and output drivers. Analog input signals processed are:

– Coupler/detector voltages from GSM and PCN band power amplifier outputs.

– Base band DAC ramp signal. – Temperature compensation diode voltages. – Pre-bias voltage for faster PA control. Selection of the GSM or PCN output driver is made using the

GSM/PCN band select pin. The On/OFF pin allows rapid power up or shutdown of the

device during Tx or Rx slots. In the off mode, both output drivers are set low for PA shutdown. In the on mode, the non-active driver will remain low for continued PAshutdown. A single external capacitor/resistor combination is used to adjust the closed loop frequency response.

The LMV248 replaces multiple discrete parts, reducing board area and cost. The LLP leadless package minimizes board footprint and permits flexible optimized PCB placement.

Features

n Multi-band cellular operation (example: GSM, PCN) n Support of GaAs HBT and bipolar technology n Shutdown mode for power save in Rx slot (0.15µA) n Integrated ramp filter n Built-in current source for biasing Schottky diodes n Pre-biasing of PA control gate voltage (V n GPRS compliant n External loop compensation n Detector diode temperature compensation n Miniature packaging: LLP-16: 4mm x 4mm x 0.8mm

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Applications

n GSM mobile phone n TDMA RF control n Wireless LAN n PC and PDA modules n GPS navigation modules

Connection Diagram

16-Pin LLP

Top View

Typical Application Circuit

10137201

10137202

FIGURE 1.

Absolute Maximum Ratings (Note 1)

If Military/Aerospace specified devices are required,

LMV248

please contact the National Semiconductor Sales Office/ Distributors for availability and specifications.

Operating Temperature −40˚C Storage Temperature Range −65˚C to 150˚C Lead Temperature (solder, 4

sec) 260˚C

ESD Tolerance

Human Body Model (Note 1) 1500V Machine Model 100V

Supply Voltage

to GND 5.5V

Input Voltage Range

VfA, VfB, or TC to GND 10V Ramp 0 to V V

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0toV

DD DD

Junction Temperature 150˚C max

Operating Ratings (Note 1)

Supply Voltage

to GND 2.5V to 5V

Input Voltage

VfA, VfB, or TC to V Ramp 0.2V to 1.8V V

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Temperature Range −20˚C ≤ T

DC and AC Electrical Characteristics

Unless otherwise specified, all limits guaranteed for VDD= 2.8V, GND = 0V, TJ= 25˚C. Boldface limits apply at temperature range extremes of operating conditions.

Symbol Parameter Condition Min

(Note 7)

OUT

A, B V

OUT

A, B

Positive Output Voltage Swing A, B

Negative Output Voltage Swing A, B

Sourcing 6mA, Tx_En = High (Note 3)

Sinking 2mA,

= 0V 0.075 0.15 V

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Tx_En = High (Note 3,4,5)

OUT

A, B V

Negative Output Voltage Swing A,B

Input Offset Voltage (Note 6) 60 80 100 mV

Sinking 2mA, TX_EN = Low (Note 3,4,5)

BW Bandwidth (−3dB) Rf = 50k, No External Frequency

Compensation

SR Output Slew Rate No External Frequency

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=0V

VHOME

Tx_En

VfA

VfB

Compensation, V

Current into V

Pin (Note 7)

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Current into BS Pin (Note 7) Current into En Pin (Note 7) Forward Bias Current Sources (Note 7) 7 10 13 µA

Temperature Compensation

(Note 7) 7 10 13 µA

Current Source

Vf-TC

Match

Current Source Matching ITC/I

ITC/I

VfA VfB

(Note 7)

LOW

BS or Tx_En Logic Low Input

(Note 7) 0.8 V

Level

HIGH

BS or Tx_En Logic High Input

(Note 7) 1.8 V

Level

d: Tx_En

Supply Current in Shutdown Tx_En = 0V 0.15 Vramp Deadband (Note 7) 160 200 mV Output Delay: Tx_En to

Output

V A,B

OUT

Positive Supply Current V

OUT=VDD/2

(Note 6) 1.1 1.8 mA

Threshold Select Voltages Tx_En = High, V

(Note 3, 4, and 5)

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=2V

2.6 2.7 V

3 5.5 V/µs

1.60 2 2.40 V

Typ

(Note 8)

Max

(Note 7)

0.06 0.15 V

1 MHz

< < <

12%

3.5 6 µs

85˚C

0V to 5V

0V to 2V

≤ 85˚C

Units

5 µA 5 µA 5 µA

5 µA

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DC and AC Electrical Characteristics (Continued)

Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is

intended to be functional, but specific performance is not guaranteed. For guaranteed specifications and the test conditions, see the Electrical Characteristics.

Note 2: Human Body Model (HBM) is 1.5kΩ in series with 100pF. Note 3: The output is not short circuit protected internally. External protection is necessary to prevent overheating and destruction or adverse reliability. Note 4: Transients and spikes during V Note 5: No overshoot above100mVoccurs when Tx_En is switched high to low or low to high. The overshoot is influenced by the external compensation capacitor. Note 6: Tested in closed loop configuration. Note 7: All limits are guaranteed by design or statistical analysis. Note 8: Typical values represent the most likely parametric norm.

on transition are allowed only as described in the diagram.

Ordering Information

Package Part Number Packaging Marking Transport Media NSC

Drawing

16-Pin LLP

LMV248LQ LMV248 1k Units Tape and Reel

LMV248LQX LMV248 4.5k Units Tape and Reel

LQA16A

LMV248

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Typical Performance Characteristics

LMV248

Error Amp Closed Loop Gain and Phase

(Rf=R

= 137k, AV−2.8)

COMP

Error Amp Open Loop Gain and Phase

(Rf=R

= 137k, AV−2.8)

COMP

10137203

SUPPLY

vs. V

10137205 10137206

Voltage Drop (Sinking)

VfA or VfB vs. Ramp Output Fallback Voltage Out A or Out B vs. V

10137204

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10137207 10137208

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