STB7720L 2.4-2.5 GHz Silicon Linear Power Amplifier IC PRELIMINARY DATA FEATURES SUMMARY * EXCELLENT LINEARITY EVM 2% @ 19dBm (WITH 802.11g OFDM 54Mb/s MODULATION) Figure 1. Package * VERY LOW QUIESCENT CURRENT (60mA) * INTEGRATED LINEAR ANALOG CONTROL FOR DC CURRENT AND OUTPUT MANAGEMENT * INTEGRATED AVERAGE CHANNEL POWER DETECTOR QFN16L (3x3) * LEADLESS PACKAGE (3mmx3mm LEAD FREE) APPLICATIONS * OPTIMIZED FOR USE IN 802.11 b/g DESCRIPTION The STB7720L, manufactured in the third generation of ST proprietary pure Si bipolar process, is a three-stage linear power amplifier (PA) optimized for 802.11b/g wireless LAN (WLAN) applications in the 2.4GHz ISM band. It features 32dB of power gain and delivers 19dBm of linear output power with an EVM degradation of only 2% under 802.11g Modulation (54Mbps). The current consumption is as low as 125mA at 19dBm make the STB7720L a good solution for mobile applications. It achieves less than -40dBc firstside lobe suppression and less than -52dBc secondside lobe suppression under 802.11b modulation (11Mbps). The device embeds a Linear Analog Control for DC current and output management and a Proprietary Average Channel Power Detector solution. This power detector has 20dB dynamic range with 1 voltage range and 0.3dB accuracy under 2:1 load mismatch. It provides a buffered DC voltage proportional to the average channel output power. Thanks to this solution we save cost and space by removing a coupler, an op amp (usually required in a power down function) and also an integrator. The SBT7720 is housed in QFN 3mmx3mm Leadless package. Table 1. Order Codes Order Codes Marking Package Packaging STB7720 7720 QFN16L (3x3) Tape & Reel Table 2. Absolute Maximum Ratings (Tamb = 25 oC) Symbol Parameter Vcc Supply voltage Tstb Storage temperature Ta Operating Ambient Temperature Pin Input Power Value Unit 5.5 V -55 to + 150 oC o -30 + 85 C 10 dBm Table 3. Thermal Data Rth(j-case) Thermal Resistance Junction-Case o TBD C/W REV. 1 August 2004 1/8 STB7720L Figure 2. Functional Block Diagram V Supply Detected Power Power Detector IN Input pre Matching Interstage Matching Interstage Matching Output Matching OUT Bias Network Quiescent C urre nt Regulation Table 4. Pin Description Figure 3. Pin Connection 16 1 15 14 13 12 TOP VIEW 2 11 3 10 EP (17) 4 5 2/8 6 7 9 8 PIN Symbol Function 1 nc - 2 RFin RF input 3 Vcnt Power Control Voltage 4 Epd Enable Power Detector 5 Vcc Supply Voltage 6 VDET Power Detector Voltage 7 nc - 8 nc - 9 nc - 10 RFout RF output 11 RFout RF output 12 nc - 13 nc - 14 Vcc Supply Voltage 15 nc - 16 Vcc Supply Voltage EP GND Ground STB7720L Table 5. Electrical Characteristics (Tamd = 25 oC, Vcc=3.3V, f=2.45GHz, Vcnt = 2.9V) Symbol Parameter f Test Conditions Min. Typ. Max. Unit Frequency 2.4 2.45 2.5 GHz Vcc Supply Voltage 3.0 3.3 3.6 V Icc(1) Current Consumption Gp P1dB Pout = 19 dBm 125 mA Power Gain 32 dB P1dB Compression 25 dBm Gain variation over Frequency -/+ 0.5 dB Gain variation over Temperature -/+ 0.5 dB Quiescent Current 60 mA EVM(1) Error Vector Magnitude Pout = 19 dBm 2 % ACPR(2) Adiacent Channel Power Ratio Pout = 19dBm, 1st Side Lobe Pout = 19dBm, 2nd Side Lobe -40 -52 dBc dBc Vdet Output Detector Voltage Range 1 V Output Detector Voltage Response Time 4 s 2nd to 5th Harmonics -40 dBc Spurious (stability)(3) Load VSWR 10:1 Turn On Time(4) -65 dBc 0.5 s Notes: (1) Parameter measured with RF modulation based on IEEE 802.11g standard (OFDM 54Mbps) (2) Parameter measured with RF modulation based on IEEE 802.11b standard (CCK 11Mbps) (3) Load VSWR is set to 10:1 and the angle is varied 360 degrees. Pout = -30 dBm to P1dB (4) Measured from Device On signal turn on to the point where RF Pout stabilizes to 0.5dB 3/8 STB7720L TYPICAL PERFORMANCE Figure 4. Supply Current Vs Output Power Figure 5. EVM Vs Output Power 275 8 250 7 225 6 200 5 EVM (%) Ic (mA) 175 150 125 4 3 100 75 2 50 1 25 Tc = +25 C 0 0 0 5 10 15 20 25 3 5 7 9 Pout (dBm) 13 15 17 19 21 Figure 7. Power Gain Vs Frequency Figure 6. Power Gain Vs Output Power 40 11 Pout (dBm) 34 Temp. depend. Temp. depend. 38 36 Tc = -30 C Tc =+25 C 33 32 Gain (dB) Gain (dB) 34 Tc =+85 C 30 28 Tc =+85 C 32 26 Tc =+25 C 31 Tc = -30 C 24 22 20 0 5 10 15 Pout (dBm) 20 25 30 2400 30 2440 2460 2480 2500 f (MHz) Figure 9. Power Detector Voltage Vs Pout Figure 8. Power Detector Voltage Vs Pout 1600 1600 Temp. depend. Vcc. depend. 1400 1400 1200 1200 Vdet (mV) Vdet (mV) 2420 1000 800 1000 800 Tc = +85 C 600 600 Tc = +25 C Tc = -30 C @ 3V, 3.3V, 3.6V 400 400 0 5 10 15 Pout (dBm) 4/8 20 25 0 5 10 15 Pout (dBm) 20 25 STB7720L Figure 10. Circuit Schematic Cn1 1 2 3 4 5 Vcc (3.3V) VEpd Vcnt (2.9V) + C1 10uF Vcc (3.3V) Vcc (3.3V) CON5 Vcc (3.3V) C10 100nF C5 1nF 4 NC Vcc Vcnt RFout Epd NC 12 L2 INDUCTOR RF OUT 11 C12 8pF 10 C14 1pF C13 1.5pF SMA S2 9 NC 3 Vcnt (2.9V) RFout Vcc ELISA01 8 VEpd 7 C2 1.5p RFIN 6 S1 NC 5 SMA NC NC 2 Vdet 1 NC Vcc L1 RF IN /4 @ 4 Harmonic 13 C11 10pF /4 @ 3 Harmonic C9 10pF 14 C4 10pF 16 C8 100nF 15 C3 100nF C6 1nF C7 1uF Vcc (3.3V) R1 10KOhm TP1 5/8 STB7720L PACKAGE MECHANICAL Table 6. Mechanical Data - Leadless PACKAGE Exposed Pad (3mm x 3mm) DIM. mm MIN. TYP. MAX A 0.80 0.90 1.00 A1 0 0.02 0.05 A3 b 0.20 REF 0.18 D D2 1.30 1.55 1.45 1.55 0.50 BSC 0.30 0.40 N 16 ND 4 NE 4 Figure 11. Package Dimensions 6/8 1.45 3.00 BSC e L 0.30 3.00 BSC 1.30 E E2 0.23 0.50 STB7720L REVISION HISTORY Table 7. Revision History Date Revision 2 August 2004 1 Description of Changes First Release 7/8 STB7720L Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics. The ST logo is registered trademark of STMicroelectronics 2004 STMicroelectronics - All Rights Reserved All other names are the property of their respective owners. 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