LTC1957-2

LTC1957-1/LTC1957-2 Single/Dual Band RF Power Controllers with 40dB Dynamic Range FEATURES s s DESCRIPTIO s s s s s s s s s s s s s s s Dual Band RF Power Amplifier Control (LTC1957-2) Internal Schottky Diode Detector with Improved Dynamic Range vs the LTC1757A Wide Input Frequency Range: 850MHz to 2GHz Autozero Loop Cancels Offset Errors and Temperature Dependent Offsets Wide VIN Range: 2.7V to 6V Allows Direct Connection to Battery RF Output Power Set by External DAC Fast Acquire After Transmit Enable Internal Frequency Compensation Rail-to-Rail Power Control Outputs Power Control Signal Overvoltage Protection Low Operating Current: 1mA Very Low Shutdown Current: < 1µA Available in a 8-Pin MSOP Package (LTC1957-1) and 10-Pin MSOP (LTC1957-2) Pin Compatible with the LTC1757A-X Improved Start Voltage Accuracy and Range Improved PCTL Input Filtering The LTC®1957-2 is a dual band RF power controller for power amplifiers operating in the 850MHz to 2GHz range. The input voltage range is optimized for operation from a single lithium-ion cell or 3 × NiMH. Several functions required for RF power control and protection are integrated in one small 10-pin MSOP package, thereby minimizing PCB area. The LTC1957-1 is a single output RF power controller that is identical in performance to the LTC1957-2 except that one output (VPCA) is provided. The LTC1957-1 can be used to drive a single RF or dual channel module with integral multiplexer. This part is available in an 8-pin MSOP package. RF power is controlled by driving the RF amplifier power control pins and sensing the resultant RF output power via a directional coupler. The RF sense voltage is peak detected using an on-chip Schottky diode. This detected voltage is compared to the DAC voltage at the PCTL pin to control the output power. The RF power amplifier is protected against high supply current and high power control pin voltages. Internal and external offsets are cancelled over temperature by an autozero control loop, allowing accurate low power programming. The shutdown feature disables the part and reduces the supply current to < 1µA. , LTC and LT are registered trademarks of Linear Technology Corporation. APPLICATIO S s s s s Single and Dual Band GSM/GPRS Cellular Telephones PCS Devices Wireless Data Modems U.S. TDMA Cellular Phones TYPICAL APPLICATIO 68Ω VIN 33pF Li-Ion SHDN BSEL LTC1957-2 Dual Band Cellular Telephone Transmitter LTC1957-2 1 2 3 4 5 VIN RF SHDN BSEL GND VCC VPCA VPCB TXEN PCTL 10 9 8 7 6 900MHz TXEN RF PA DIRECTIONAL COUPLER DIPLEXER DAC 1.8GHz /1.9GHz RF PA U 50Ω 1957 TA01 U U 1 LTC1957-1/LTC1957-2 ABSOLUTE AXI U RATI GS VIN to GND ............................................... – 0.3V to 6.5V VPCA, VPCB Voltage ..................................... – 0.3V to 3V PCTL Voltage ............................... – 0.3V to (VIN + 0.3V) RF Voltage ........................................ (VIN – 2.2V) to 7V IVCC, Continuous ....................................................... 1A IVCC, 12.5% Duty Cycle .......................................... 2.5A SHDN, TXEN, BSEL Voltage to GND ............................ – 0.3V to (VIN + 0.3V) PACKAGE/ORDER I FOR ATIO TOP VIEW VIN RF SHDN GND 1 2 3 4 8 7 6 5 VCC VPCA TXEN PCTL ORDER PART NUMBER LTC1957-1EMS8 MS8 PART MARKING LTRH VIN RF SHDN BSEL GND 1 2 3 4 5 MS8 PACKAGE 8-LEAD PLASTIC MSOP TJMAX = 125°C, θJA = 160°C/W Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS PARAMETER VIN Operating Voltage IVIN Shutdown Current IVIN Autozero Current IVIN Operating Current IVCC Current Limit VIN to VCC Resistance VPCA/B VOL VPCA/B Dropout Voltage VPCA/B Voltage Clamp VPCA/B Output Current VPCA/B Enable Time VPCA/B Bandwidth VPCA/B Load Capacitance VPCA/B Slew Rate VPCA/B Droop VPCA/B TXEN Start Voltage SHDN = LO, TXEN = LO CONDITIONS The q denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = 3.6V, SHDN = TXEN = HI, unless otherwise noted. MIN q SHDN = LO, TXEN = LO, BSEL = LO SHDN = HI, TXEN = LO SHDN = HI, TXEN = HI, IVPCA = IVPCB = 0mA, VPCA/B = HI TXEN = HI, Open Loop, PCTL = –100mV ILOAD = 5.5mA, VIN = 2.7V RLOAD = 400Ω, PCTL = 2V, External Gain = 0.417 VPCA/B = 2.4V, VIN = 2.7V VPCA/B = 2.6V, VIN = 3V VPCTL = 2V Step, CLOAD = 100pF (Note 5) CLOAD = 100pF, RLOAD = 400Ω (Note 8) (Note 6) VPCTL = 2V Step, CLOAD = 100pF (Note 3) VIN = 2.7V, VPCTL = 2V Step Open Loop, TXEN Low to High, CLOAD = 100pF (Note 9) 2 U U W WW U W (Note 1) IVPCA/B, 25% Duty Cycle ...................................... 20mA Operating Temperature Range (Note 2) . – 30°C to 85°C Storage Temperature Range ................ – 65°C to 150°C Maximum Junction Temperature ........................ 125°C Lead Temperature (Soldering, 10 sec)................ 300°C TOP VIEW 10 9 8 7 6 VCC VPCA VPCB TXEN PCTL ORDER PART NUMBER LTC1957-2EMS MS10 PART MARKING LTRJ MS10 PACKAGE 10-LEAD PLASTIC MSOP TJMAX = 125°C, θJA = 160°C/W TYP MAX 6 1 UNITS V µA mA mA A mΩ V V V mA mA 2.7 1 1.1 2.2 90 q q 1.6 1.7 150 0.1 VIN – 0.28 3.0 q q q q q q q 0 2.7 5.5 6.0 280 1.2 500 2.85 9 10 440 370 2.2 ±1 600 650 500 100 ns kHz pF V/µs µV/ms q 700 mV LTC1957-1/LTC1957-2 The q denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = 3.6V, SHDN = TXEN = VIN, unless otherwise noted. PARAMETER SHDN Input Threshold TXEN, BSEL Input Threshold SHDN, TXEN, BSEL Input Current PCTL Input Voltage Control Range PCTL Input Voltage Range PCTL Input Resistance PCTL Input Filter Autozero Range Autozero Settling Time (tS) RF Input Frequency Range RF Input Power Range RF Input Impedance BSEL Timing VIN = 2.7V, RLOAD = 400Ω (Note 4) tS, Shutdown to Enable (Autozero), VIN = 2.7V (Note 10) (Note 6) 900MHz (Note 6) 1800MHz (Note 6) Referenced to VIN, SHDN = LO, TXEN = LO t1, Setup Time Prior to TXEN Asserted High t2, Hold Time After TXEN is Asserted Low q q q q ELECTRICAL CHARACTERISTICS CONDITIONS MIN q q q q q q TYP MAX 1.4 1.4 UNITS V V µA V V kΩ kHz mV µs MHz dBm dBm Ω ns ns VIN = 2.7V to 6V, TXEN = LO VIN = 2.7V to 6V SHDN, TXEN or BSEL = 3.6V VIN = 3V to 6V, RLOAD = 400Ω VIN = 3V, RLOAD = 400Ω (Note 7) SHDN = LO, TXEN = LO 0.35 0.35 10 0 50 90 350 25 50 2 2.4 140 400 50 850 – 26 –24 100 200 200 200 2000 16 16 350 Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: The LTC1957-1 and LTC1957-2 are guaranteed to meet performance specifications from 0°C to 70°C. Specifications over the – 30°C to 85°C operating temperature range are assured by design, characterization and correlation with statistical process controls. Note 3: Slew rate is measured open loop. The slew time at VPCA or VPCB is measured between 1V and 2V. Note 4: Maximum DAC zero-scale offset voltage that can be applied to PCTL. Note 5: This is the time from TXEN rising edge 50% switch point to VPCA/B = 1V. Note 6: Guaranteed by design. This parameter is not production tested. Note 7: Includes maximum DAC offset voltage and maximum control voltage. Note 8: Bandwidth is calculated using the 10% to 90% rise time: BW = 0.35/rise time Note 9: Measured 1µs after TXEN = HI. Note 10: 50% switch point, SHDN HI = VIN, TXEN HI = VIN. 3 LTC1957-1/LTC1957-2 TYPICAL PERFOR A CE CHARACTERISTICS PCTL REFERENCED DETECTOR OUTPUT VOLTAGE (mV) PCTL REFERENCED DETECTOR OUTPUT VOLTAGE (mV) Detector Characteristics at 900MHz 10000 VIN = 3V TO 4.4V 1000 100 –30°C 10 1 –26 –20 –14 –8 –2 4 RF INPUT POWER (dBm) PI FU CTIO S (LTC1957-2/LTC1957-1) VIN (Pin 1): Input Supply Voltage, 2.7V to 6V. VIN should be bypassed with 0.1µF and 100pF ceramic capacitors. Used as return for RF 200Ω termination. RF (Pin 2): RF Feedback Voltage from the Directional Coupler. Referenced to VIN. A coupling capacitor of 33pF must be used to connect to the ground referenced directional coupler. The frequency range is 850MHz to 2000MHz. This pin has an internal 200Ω termination, an internal Schottky diode detector and peak detector capacitor. SHDN (Pin 3): Shutdown Input. A logic low on the SHDN pin places the part in shutdown mode. A logic high places the part in autozero when TXEN is low. SHDN has an internal 150k pull-down resistor to ensure that the part is in shutdown when the drivers are in a three-state condition. BSEL (Pin 4): (LTC1957-2 Only) Selects VPCA when low and VPCB when high. This input has an internal 150k resistor to ground. GND (Pin 5/Pin 4): System Ground. PCTL (Pin 6/Pin 5): Analog Input. The external power control DAC drives this input. The amplifier servos the RF 4 UW 75°C 25°C Detector Characteristics at 1800MHz 10000 VIN = 3V TO 4.4V 1000 100 –30°C 10 75°C 1 –24 –20 –16 –12 –8 –4 0 4 8 RF INPUT POWER (dBm) 25°C 10 16 12 16 1957 G02 1957 G01 U U U power until the RF detected signal equals the DAC signal. The input impedance is typically 90kΩ. TXEN (Pin 7/Pin 6): Transmit Enable Input. A logic high enables the control amplifier. When TXEN is low and SHDN is high the part is in the autozero mode. This input has an internal 150k resistor to ground. VPCB (Pin 8): (LTC1957-2 Only) Power Control Voltage Output. This pin drives an external RF power amplifier power control pin. The maximum load capacitance is 100pF. The output is capable of rail-to-rail swings at low load currents. Selected when BSEL is high. VPCA (Pin 9/Pin 7): Power Control Voltage Output. This pin drives an external RF power amplifier power control pin. The maximum load capacitance is 100pF. The output is capable of rail-to-rail swings at low load currents. Selected when BSEL is low (LTC1957-2 only). VCC (Pin 10/Pin 8): RF Power Amplifier Supply. This pin has an internal 0.050Ω sense resistor between VIN and VCC that senses the RF power amplifier supply current to detect overcurrent conditions. LTC1957-1/LTC1957-2 BLOCK DIAGRA 10 VCC 0.02Ω RSENSE 0.05Ω METAL 68Ω – CS 33pF + OFFSET TRIM 200Ω VIN PROGRAMMABLE 200Ω 33k 35k 28pF 35k 60µA 5 GND COMPRESSION BG1 THERMAL SHUTDOWN 22k 22k TSDB TSDB TXENI 150k MUX CONTROL PA 60µA ICL CC 400µA 140k VPC RFDET gm 22k 1.2V 33k BG1 1.2V BANDGAP 1.2V ADJUSTABLE 12Ω PB 100Ω 12Ω 100Ω 110k GAIN TRIM gm 50mV FILTER 2 RF OPERATE SHDN 150k W 3 (LTC1957-2) DIPLEXER 900MHz RF PA 50Ω RF PA 1.8GHz/1.9GHz Li-Ion 1 VIN 0.02Ω 100Ω METAL TXENB AUTOZERO – AZ PA VPCA ADJUSTABLE 9 OVERCURRENT + + CAMP PB VPCB 8 –+ – + – XMT AUTOZERO 150k SHDN 7 TXEN 6 PCTL 4 BSEL 1957 BD 5 LTC1957-1/LTC1957-2 APPLICATIONS INFORMATION Forward The LTC1957 is an improved version of the LTC1757A. The Schottky diode detector dynamic range has been extended to over 40dB. The start voltage accuracy has been improved to ±17%. The autozero hold time has been increased for applications requiring transmit times of several hundred milliseconds. The PCTL input filter bandwidth has been reduced to 350kHz for improved rejection of DAC noise as well as smoother ramp shaping. Operation The LTC1957-2 dual band RF power control amplifier integrates several functions to provide RF power control over frequencies ranging from 850MHz to 2GHz. The device also prevents damage to the RF power amplifier due to overvoltage or overcurrent conditions. These functions include an internally compensated power control, amplifier to control the RF output power, an autozero section to cancel internal and external voltage offsets, a sense amplifier with an internal sense resistor to limit the maximum RF power amplifier current, an RF Schottky diode peak detector and amplifier to convert the RF feedback signal to DC, a VPCA/B overvoltage clamp, compression, a bandgap reference, a thermal shutdown circuit and a multiplexer to switch the control amplifier output to either VPCA or VPCB. Band Selection The LTC1957-2 is designed for dual band operation. The BSEL pin will select output VPCA when low and output VPCB when high. For example, VPCA could be used to drive a 900MHz channel and VPCB a 1.8GHz/1.9GHz channel. BSEL must be established before the part is enabled. The LTC1957-1 can be used to drive a single RF channel or dual channel with integral multiplexer. Control Amplifier The control amplifier supplies the power control voltage to the RF power amplifier. A portion (typically – 19dB for low frequencies and –14dB for high frequencies) of the RF output voltage is sampled, via a directional coupler, to close the gain control loop. When a DAC voltage is applied to PCTL, the amplifier quickly servos VPCA or VPCB positive until the detected feedback voltage applied to the RF pin matches the voltage at PCTL. This feedback loop provides accurate RF power control. VPCA or VPCB are capable of driving a 5.5mA load current and 100pF load capacitor. RF Detector The internal RF Schottky diode peak detector and amplifier converts the RF feedback voltage from the directional coupler to a low frequency voltage. This voltage is compared to the DAC voltage at the PCTL pin by the control amplifier to close the RF power control loop. The RF pin input resistance is typically 200Ω and the frequency range of this pin is 850MHz to 2000MHz. The detector demonstrates excellent efficiency and linearity over a wide range of input power. The Schottky detector is biased at about 60µA and drives an on-chip peak detector capacitor of 28pF. Autozero An autozero system is included to improve power programming accuracy over temperature. This section cancels internal offsets associated with the Schottky diode detector and control amplifier. External offsets associated with the DAC driving the PCTL pin are also cancelled. Offset drift due to temperature is cancelled between each burst. The maximum offset allowed at the DAC output is limited to 400mV. Autozeroing is performed when the part is in autozero mode (SHDN = high, TXEN = low). When the part is enabled (TXEN = high, SHDN = high) the autozero capacitors are held and the VPCA or VPCB pin is connected to the control amplifier output. The hold droop voltage of typically < 1µV/ms provides for accurate offset 6 U W U U LTC1957-1/LTC1957-2 APPLICATIONS INFORMATION cancellation over the normal 1/8 duty cycle associated with the GSM protocol as well as multislot protocols. The part must be in the autozero mode for at least 50µs for autozero to settle to the correct value. Filter There is a 350kHz filter included in the PCTL path. Protection Features The RF power amplifier is overcurrent protected by an internal sense amplifier. The sense amplifier measures the voltage across an internal 0.050Ω resistor to determine the RF power amplifier current. VPCA or VPCB is lowered as this supply current exceeds 2.2A, thereby regulating the current to about 2.25A. The regulated current limit is temperature compensated. The 0.050Ω resistor and the current limit feature can be removed by connecting the PA directly to VIN. The RF power amplifier control voltage pins are overvoltage protected. The VPC overvoltage clamp regulates VPCA or VPCB to 2.85V when the gain and PCTL input combination attempts to exceed this voltage. The internal thermal shutdown circuit will disable the LTC1957-2 if the junction temperature exceeds approximately 150°C. The part will be enabled when the temperature falls below 140°C. Modes of Operation The LTC1957-2 supports three operating modes: shutdown, autozero and enable. In shutdown mode (SHDN = Low) the part is disabled and supply currents will be reduced to 640mV LTC1957-1/LTC1957-2 APPLICATIO S I FOR ATIO + PCTL CONTROL AMPLIFER BW1 ≅ 370kHz RF POWER AMP VPCA/B G1 G2 – IFB LTC1957 H1 RF H2 1957 F05 VOLTAGE GAIN (dB) CONTROLLED RF OUTPUT POWER RF DETECTOR DIRECTIONAL COUPLER 14dB to 20dB LOSS Figure 5. Closed Loop Block Diagram External pole frequencies within the loop will further reduce phase margin. The phase margin degradation, due to external and internal pole combinations, is difficult to determine since complex poles are present. Gain peaking may occur, resulting in higher bandwidth and lower phase margin than predicted from the open loop Bode plot. A low frequency AC SPICE model of the LTC1957 power controller is included to better determine pole and zero interactions. The user can apply external gains and poles to determine bandwidth and phase margin. DC, transient and RF information cannot be extracted from the present model. The model is suitable for external gain evaluations up to 6 ×. The 350kHz PCTL input filter limits the bandwidth, therefore, use the RF input as demonstrated in the model. This model (Figure 7) is being supplied to LTC users as an aid to circuit designs. While the model reflects reasonably close similarity to corresponding devices in low frequency AC performance terms, its use is not suggested as a replacement for breadboarding. Simulation should be used as a forerunner or a supplement to traditional lab testing. Users should note very carefully the following factors regarding this model: Model performance in general will reflect typical baseline specs for a given device, and certain aspects of performance may not be modeled fully. While reasonable care has been taken in the preparation, we cannot be responsible for correct application on any and all computer systems. Model users are hereby notified that these models are supplied “as is”, with no direct or implied responsibility on the part of LTC for their operation U 80 70 60 50 40 30 20 10 0 –10 –20 –30 –40 –50 –60 100 1k 180 RLOAD = 2k 160 CLOAD = 33pF 140 120 PHASE 100 80 GAIN 60 40 20 0 –20 –40 –60 –80 –100 10k 100k 1M 10M FREQUENCY (Hz) 1957 F06 W UU PHASE (DEG) Figure 6. SPICE Model Open Loop Gain and Phase Characteristics from RF to VPCA, PCTL < 640mV within a customer circuit or system. Further, Linear Technology Corporation reserves the right to change these models without prior notice. In all cases, the current data sheet information is your final design guideline, and is the only performance guarantee. For further technical information, refer to individual device data sheets. Your feedback and suggestions on this model is appreciated. Linear Technology Corporation hereby grants the users of this model a nonexclusive, nontransferable license to use this model under the following conditions: The user agrees that this model is licensed from Linear Technology and agrees that the model may be used, loaned, given away or included in other model libraries as long as this notice and the model in its entirety and unchanged is included. No right to make derivative works or modifications to the model is granted hereby. All such rights are reserved. This model is provided as is. Linear Technology makes no warranty, either expressed or implied about the suitability or fitness of this model for any particular purpose. In no event will Linear Technology be liable for special, collateral, 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. 11 LTC1957-1/LTC1957-2 APPLICATIO S I FOR ATIO *LTC1957 Low Frequency AC Spice Model* GIN1 ND2 0 ND1A IFB 100E-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 GX7 ND12 0 0 ND11 1E-6 GX6 ND11 0 0 ND10 1E-6 GXFB IFB 0 0 ND14 28.8E-6 EX1 ND8 0 0 ND7 1 RPCTL2 ND1 0 33E3 RFILT ND1 ND1A 50E3 RO1 ND2 0 70E6 RX3 ND6 0 1E6 RX4 ND7 0 1E6 RPCTL1 PCTL ND1 53E3 RX1 ND3 0 1E6 RX2 ND4 ND5 1E6 RSD RF ND9 500 RX5 ND10 0 1E6 RT RF 0 250 RX8 ND14 0 1E6 RX7 ND12 ND13 1E6 RX6 ND11 0 1E6 R9 ND8 ND8A 100 R9A ND8A VPCA 20 RLOAD VPCA 0 2E3 RFB1 IFB 0 22E3 CPCTL1 ND1A 0 7E-12 CX3 ND6 0 8E-15 CX4 ND7 0 12E-15 CC1 ND2 0 24E-12 CX1 ND3 0 2E-15 CX5 ND10 0 10E-15 CX6 ND11 0 1.2E-15 CLOAD VPCA 0 33E-12 CLINT ND8A 0 37E-12 CLINTA VPCA 0 18E-12 CFB1 IFB 0 300E-15 CP ND9 0 28E-12 LX2 ND5 0 34E-3 LX7 ND13 0 7E-3 **Closed loop connections, comment-out VPCTLO, VRF, Adjust EFB gain to reflect external gain, currently set at 3X** *EFB RF 0 VPCA VIN 3 VIN VIN 0 DC 0 AC 1 *VPCTLO PCTL 0 DC 0 **Open loop connections, comment-out EFB, VIN and VPCTLO** VPCTLO PCTL 0 DC 0 VRF RF 0 DC 0 AC 1 **Add AC statement and print statement as required** .AC DEC 50 100 1E7 .END Figure 7. LTC1957 Low Frequency AC SPICE Model 12 U W UU RPCTL1 53E3 ND2 ND4 GIN1 ND3 ND6 ND7 ND1 ND1A + RO1 70E6 GM GM GM GM 100E-6 CC1 24E-12 CX1 2E-15 CX3 8E-15 RX1 1E6 1E-6 RX3 1E6 1E-6 + – 1E-6 LX2 34E-3 GX1 + – – – GX2 + GX3 + GX4 RX4 1E6 1E-6 CX4 12E-15 CPCTL1 7E-12 – 24MHz POLE GXFB + EX1 VAMP GM + RFB1 22E3 CFB1 300E-15 R9 ND8 100Ω ND8A R9A 20Ω VPCA CLINT 37E-12 CLINTA 18E-12 RLOAD 2E3 CLOAD 33E-12 – 28.8E-6 – 16MHz POLE ND10 ND11 130MHz POLE 23MHz ZERO ND12 ND14 GX7 RF RT 200Ω + GM RX5 1E6 GM 1E-6 CX5 10E-15 RX6 1E6 1E-6 CX6 1.2E-15 GX5 + – GX6 + GM + GM GX8 RX7 1E6 ND13 RX8 1E6 RSD 500Ω ND9 CP 28E-12 – – 1E-6 LX7 7E-3 – 1E-6 1957 F08 Figure 8. LTC1957 Low Frequency AC Model U LTC1957-1/LTC1957-2 APPLICATIO S I FOR ATIO IFB W RPCTL2 33E3 RFILT 50E3 GM RX2 1E6 ND5 UU PCTL 100Hz POLE 80MHz POLE 5MHz ZERO 13MHz POLE 20MHz POLE 13 LTC1957-1/LTC1957-2 PACKAGE DESCRIPTIO 0.007 (0.18) 0.021 ± 0.006 (0.53 ± 0.015) * DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE ** DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS. INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE 14 U MS8 Package 8-Lead Plastic MSOP (Reference LTC DWG # 05-08-1660) 0.118 ± 0.004* (3.00 ± 0.102) 8 76 5 0.193 ± 0.006 (4.90 ± 0.15) 0.118 ± 0.004** (3.00 ± 0.102) 1 0.043 (1.10) MAX 0° – 6° TYP SEATING PLANE 23 4 0.034 (0.86) REF 0.009 – 0.015 (0.22 – 0.38) 0.0256 (0.65) BSC 0.005 ± 0.002 (0.13 ± 0.05) MSOP (MS8) 1100 LTC1957-1/LTC1957-2 PACKAGE DESCRIPTIO 0.007 (0.18) 0.021 ± 0.006 (0.53 ± 0.015) * DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE ** DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS. INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE 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 representation that the interconnection of its circuits as described herein will not infringe on existing patent rights. U MS10 Package 10-Lead Plastic MSOP (Reference LTC DWG # 05-08-1661) 0.118 ± 0.004* (3.00 ± 0.102) 10 9 8 7 6 0.193 ± 0.006 (4.90 ± 0.15) 0.118 ± 0.004** (3.00 ± 0.102) 12345 0.043 (1.10) MAX 0° – 6° TYP SEATING PLANE 0.007 – 0.011 (0.17 – 0.27) 0.034 (0.86) REF 0.0197 (0.50) BSC 0.005 ± 0.002 (0.13 ± 0.05) MSOP (MS10) 1100 15 LTC1957-1/LTC1957-2 TYPICAL APPLICATION Single Band Cellular Telephone Transmitter 68Ω VIN 33pF Li-Ion SHDN LTC1957-1 1 2 3 4 VIN RF SHDN GND VCC VPCA TXEN PCTL 8 7 6 5 TXEN RF IN RF PA DIRECTIONAL COUPLER Dual Band Cellular Telephone Transmitter Without Current Limiting 68Ω DIRECTIONAL COUPLER VIN Li-Ion 33pF LTC1957-1 1 2 VIN RF SHDN GND VCC VPCA TXEN PCTL 8 7 6 5 TXEN SHDN 3 4 RELATED PARTS PART NUMBER LTC1261 LTC1550/LTC1551 LTC1730 LTC1732 LTC1734 DESCRIPTION Regulated Inductorless Voltage Inverter Low Noise Inductorless Voltage Inverter Li-Ion Pulse Charger Li-Ion Linear Charger ThinSOTTM Li-Ion Linear Charger COMMENTS Regulated –5V from 3V, REG Pin Indicates Regulation, Up to 15mA, Micropower Regulated Output,