ltc1757a-2 Linear Technology Corporation, ltc1757a-2 Datasheet
ltc1757a-2
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ltc1757a-2 Summary of contents
Page 1
... MSOP package, thereby minimizing PCB area. The LTC1757A single output RF power controller that is identical in performance to the LTC1757A-2 except that one output (V be used to drive a single RF channel or dual channel module with integral multiplexer. This part is available in an 8-pin MSOP package ...
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... HI VPCA VPCB PCA 100pF (Note 5) LOAD = 400 (Note 9) LOAD = 100pF (Note 3) LOAD = 2V Step PCTL = 100pF (Note 10) LOAD ORDER PART NUMBER TOP VIEW LTC1757A-2EMS 9 V PCA 8 V PCB 7 TXEN 6 PCTL MS10 PART MARKING = 250 C/W LTPM JA MIN TYP MAX 2 0.9 1 ...
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... Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: The LTC1757A-1 and LTC1757A-2 are guaranteed to meet performance specifications from Specifications over the – operating temperature range are assured by design, characterization and correlation with statistical process controls ...
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... When TXEN is low and SHDN is high the part is in the autozero mode. This input has an internal 150k resistor to ground. V (Pin 8): (LTC1757A-2 Only) Power Control Voltage PCB Output. This pin drives an external RF power amplifier power control pin. The maximum load capacitance is 100pF ...
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... DIPLEXER 900MHz RF PA Li-Ion AUTOZERO – 50mV – + 6pF ICL + 33k RFDET – 16.7k 33k 1.2V 33k 600mV XMT AUTOZERO 150k TXEN PCTL 7 6 LTC1757A-1/LTC1757A 1.8GHz 50 TXENB PA + ADJ – CAMP – 400 A 140k VPC g 110k m 1.2V OVP g m 173k V IN 54.5k 12 ...
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... PCA Band Selection The LTC1757A-2 is designed for dual band operation. The BSEL pin will select output V when low and output V PCA when high. For example, V could be used to drive a ...
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... The feedback voltage from the directional coupler and the PCA PCB output power will be detected by the LTC1757A-2 at the RF pin. The loop closes and the amplifier output tracks the DAC voltage ramping at PCTL. The RF power output will then follow the programmed power profile from the DAC. ...
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... LTC1757A-1/LTC1757A APPLICATIO S I FOR ATIO External Termination The LTC1757A has an internal 185 termination resistor at the RF pin directional coupler is used recommended that an external 68 termination resistor be connected between the RF coupling capacitor (33pF), and ground at the side connected to the directional coupler ...
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... The LTC1757A provides a stable control loop for several RF power amplifier models from different manufacturers over a wide range of frequencies, output power levels and V conditions. However, there are several factors that SWR can improve or degrade loop frequency stability. LTC1757A-1/LTC1757A-2 3dB DIRECTIONAL ATTENUATOR COUPLER R2 33pF ...
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... LTC1757A-1/LTC1757A APPLICATIO S I FOR ATIO 1) The additional voltage gain supplied by the RF power amplifier increases the loop gain raising poles normally below the 0dB axis. The extra voltage gain can vary significantly over input/output power ranges, frequency, power supply, temperature and manufacturer. RF power amplifier gain control transfer functions are often not available and must be generated by the user ...
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... F04 200 = 33pF = 2k LOAD 150 100 50 0 –50 –100 1M 10M 1757A F06 Figure 7. SPICE Model Closed Loop Voltage Gain LTC1757A-1/LTC1757A-2 CONTROL AMPLIFER BW1 400kHz RF POWER AMP + CONTROLLED V PCA/B RF OUTPUT G1 G2 POWER – LTC1757A ...
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... LTC1757A-1/LTC1757A APPLICATIO S I FOR ATIO *LTC1757A Low Frequency AC Spice Model* GIN1 ND2 0 ND1 IFB 59E-6 GX3 ND6 0 0 ND4 1E-6 GX4 ND7 0 0 ND6 1E-6 GX1 ND3 0 0 ND2 1E-6 GX2 ND4 0 0 ND3 1E-6 GX5 ND10 0 0 ND9 1E-6 GX8 ND14 0 0 ND12 1E-6 ...
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... In no event will Linear Technology be liable for special, collat- eral, incidental or consequential damages in connection with or arising out of the use of this model. It should be remembered that models are a simplification of the actual circuit. LTC1757A-1/LTC1757A-2 13 ...
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... LTC1757A-1/LTC1757A APPLICATIO S I FOR ATIO ...
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... Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen- tation that the interconnection of its circuits as described herein will not infringe on existing patent rights. LTC1757A-1/LTC1757A-2 U Dimensions in inches (millimeters) unless otherwise noted. ...
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... LTC1757A-1/LTC1757A-2 U TYPICAL APPLICATIO 68 33pF Li-Ion 3 SHDN 4 Using the LTC1757A Dual Band Cellular Telephone Transmitter Without Current Limiting 68 33pF LTC1757A Li-Ion RF 3 SHDN SHDN 4 GND DAC RELATED PARTS PART NUMBER DESCRIPTION LTC1261 Regulated Inductorless Voltage Inverter ...