VCA2619

VCA2619 SBOS276A − AUGUST 2003 − REVISED AUGUST 2003 Dual, Variable Gain Amplifier with Input Buffer FEATURES D GAIN RANGE: 50dB D LOW CROSSTALK: -60dB at Max Gain, fIN = 5MHz DESCRIPTION The VCA2619 is a highly integrated, dual receive channel, Variable Gain Amplifier (VGA) with analog gain control. The VCA2619s VGA section consists of two parts: the Voltage Controlled Attenuator (VCA) and the Programmable Gain Amplifier (PGA). The gain and gain range of the PGA can be digitally programmed. The combination of these two programmable elements results in a variable gain ranging from 0dB up to a maximum gain as defined by the user through external connections. The single−ended unity gain input buffer provides predictable high input impedance. The output of the VGA can be used in either a single−ended or differential mode to drive high−performance Analog−to− Digital (A/D) converters. A separate power−down pin reduces power consumption. The VCA2619 also features low crosstalk and outstanding distortion performance. The combination of low noise and gain range programmability make the VCA2619 a versatile building block in a number of applications where noise performance is critical. The VCA2619 is available in a TQFP−32 package. D HIGH−SPEED VARIABLE GAIN ADJUST D POWER SHUTDOWN MODE D HIGH IMPEDANCE INPUT BUFFER APPLICATIONS D D D D ULTRASOUND SYSTEMS WIRELESS RECEIVERS TEST EQUIPMENT RADAR 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. All trademarks are the property of their respective owners. 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. Copyright  2003, Texas Instruments Incorporated www.ti.com VCA2619 www.ti.com SBOS276A − AUGUST 2003 − REVISED AUGUST 2003 ABSOLUTE MAXIMUM RATINGS(1) Power Supply (+VS) Analog Input Logic Input Case Temperature Junction Temperature +6V −0.3V to (+VS + 0.3V) −0.3V to (+VS + 0.3V) +100°C +150°C This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage. ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications. Storage Temperature −40°C to +150°C (1) Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. Exposure to absolute maximum conditions for extended periods may affect device reliability. PACKAGE/ORDERING INFORMATION PRODUCT PACKAGE-LEAD PACKAGE DESIGNATOR(1) PBS SPECIFIED TEMPERATURE RANGE −40°C to +85°C PACKAGE MARKING VCA2619Y ORDERING NUMBER VCA2619YT VCA2619YR TRANSPORT MEDIA, QUANTITY Tape and Reel, 250 Tape and Reel, 2000 VCA2619Y TQFP−32 (1) For the most current specification and package information, refer to our web site at www.ti.com. 2 VCA2619 www.ti.com SBOS276A − AUGUST 2003 − REVISED AUGUST 2003 ELECTRICAL CHARACTERISTICS At TA = +25°C, VDD = 5V, load resistance = 500Ω on each output to ground single−ended output (1Vpp), MGS = 111, VCACNTL = 2.9V and fIN = 5MHz, unless otherwise noted. VCA2619 PARAMETER BUFFER Input Resistance Input Capacitance Input Bias Current Maximum Input Voltage Input Voltage Noise Input Current Noise Noise Figure Bandwidth PROGRAMMABLE VARIABLE GAIN AMPLIFIER Peak Input Voltage −3dB Bandwidth Slew Rate Output Signal Range Output Impedance Output Short−Circuit Current 3rd-Harmonic Distortion 2nd-Harmonic Distortion 2nd-Harmonic Distortion Overload Performance (2nd-Harmonic Distortion) Time Delay IMD, 2−Tone Crosstalk ACCURACY Gain Slope Gain Error(1) Output Offset Voltage Gain Range GAIN CONTROL INTERFACE Input Voltage (VCACNTL) Range Input Resistance Response Time POWER SUPPLY Specified Operating Range Power Dissipation Power−Down 4.75 5.0 240 9.2 5.25 300 V mW mW 45dB Gain Change 0 to 3.0 1 0.2 V MΩ µs VCACNTL = 0.4V to 2.9V VCACNTL = 0.2V to 3.0V VCACNTL = 0.4V to 2.9V VCACNTL = 0.2V to 3.0V VCACNTL = 0.4V to 2.9V 20 ±2.75 ±1.50 ±50 52 50 dB/V dB dB mV dB dB VOUT = 2Vpp, f = 9.95MHz 2Vpp Differential VOUT = 1Vpp, VCACNTL = 2.9V VOUT = 1Vpp, VCACNTL = 2.9V Differential, VOUT = 2Vpp, VCACNTL = 3.0V, MGS = 011 Input Signal = 0.5Vpp, VCACNTL = 2V −45 −42 RL ≥ 500Ω Each Side to Ground 1 20 300 2.5 ±1 1 ±40 −60 −50 −50 −40 to −45 5 −59 −60 Vpp MHz V/µs V Ω mA dBc dBc dBc dB ns dBc dB PGA Gain = 45dB, RS = 50Ω Independent of Gain RF = 550Ω, PGA Gain = 45dB, RS = 75Ω CONDITIONS MIN TYP MAX UNIT kΩ pF nA Vpp nV/√Hz fA/√Hz dB MHz 600 5 1 1 5.9 350 13 100 ±2.0 48 (1) Referenced to best fit dB−linear curve. 3 VCA2619 www.ti.com SBOS276A − AUGUST 2003 − REVISED AUGUST 2003 PIN CONFIGURATION GNDA NOUTA 25 24 23 22 21 VCA2619 5 6 7 8 20 19 18 17 POUTA 26 VDDA 28 CP2A 30 CP1A 29 NC 32 NC 31 +INA NC VDDR VBIAS VCM GNDR NC +INB 1 2 3 4 27 VCACNTL MGS3 MGS2 MGS1 PD NC NC DNC 10 11 12 13 14 15 POUTB NC NC VDDB CP2B CP1B GNDB PIN CONFIGURATION PIN 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 DESIGNATOR +INA NC VDDR VBIAS VCM GNDR NC +INB NC NC CP2B CP1B VDDB GNDB POUTB NOUTB DESCRIPTION Noninverting Input Channel A No Internal Connection Internal Reference Supply Bias Voltage Common−Mode Voltage Internal Reference Ground No Internal Connection Noninverting Input Channel B No Internal Connection No Internal Connection Coupling Capacitor Channel B Coupling Capacitor Channel B +5V Supply Channel B Ground Channel B Positive Output Channel B Negative Output Channel B 17 18 19 20 23 22 23 24 25 26 27 28 29 30 31 32 PIN DESIGNATOR DNC NC NC PD MGS1 MGS2 MGS3 VCACNTL NOUTA POUTA GNDA VDDA CP1A CP2A NC NC DESCRIPTION Do Not Connect No Internal Connection No Internal Connection Power-Down (Active LOW) Maximum Gain Select 1 (MSB) Maximum Gain Select 2 Maximum Gain Select 3 (LSB) VCA Analog Control Negative VCA Output Channel A Positive VCA Output Channel A Ground Channel A +5V Supply Channel A Coupling Capacitor Channel A Coupling Capacitor Channel A No Internal Connection No Internal Connection 4 NOUTB 16 9 VCA2619 www.ti.com SBOS276A − AUGUST 2003 − REVISED AUGUST 2003 TYPICAL CHARACTERISTICS At TA = 25°C and VDD = 5V, load resistance = 500Ω on each output to ground, differential output (2VPP) MGS = 111, and fIN = 5MHz, unless otherwise noted. GAIN vs VCA 46 42 38 34 30 26 22 18 14 10 6 2 −2 −6 − 10 − 14 MGS = 111 MGS = 110 MGS = 101 Gain Error (dB) 3.0 2.5 2.0 1.5 1.0 0.5 0 − 0.5 − 1.0 − 1.5 − 2.0 − 2.5 − 3.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 GAIN ERROR vs TEMPERATURE +85_ C +25_ C Gain (dB) MGS = 010 MGS = 011 MGS = 100 − 40_ C VCACNTL (V) 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 0.5 0.7 0.9 1.1 1.3 1.5 1.7 1.9 2.1 2.3 2.5 2.7 2.9 VCACNTL (V) GAIN ERROR vs VCACNTL 3.0 2.5 2.0 1.5 Gain Error (dB) 10MHz Gain Error (dB) 1.0 0.5 0 − 0.5 − 1.0 − 1.5 − 2.0 − 2.5 − 3.0 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 0.5 0.7 0.9 1.1 1.3 1.5 1.7 1.9 2.1 2.3 2.5 2.7 2.9 GAIN ERROR vs VCACNTL 3.0 2.5 2.0 1.5 1.0 0.5 0 − 0.5 − 1.0 − 1.5 − 2.0 − 2.5 − 3.0 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 2.9 0.5 0.7 0.9 1.1 1.3 1.5 1.7 1.9 2.1 2.3 2.5 2.7 MGS = 010 MGS = 100 5MHz 1MHz MGS = 111 VCACNTL (V) VCACNTL (V) GAIN MATCH: CHA to CHB, VCAC NT L = 2.9V GAIN MATCH: CHA to CHB, VCAC NTL = 0.4V 45 40 35 30 Units Units − 0.99 − 0.91 − 0.83 − 0.75 − 0.67 − 0.59 − 0.51 − 0.42 − 0.34 − 0.26 − 0.18 − 0.10 − 0.02 0.06 0.14 0.22 0.30 0.38 0.47 More 25 20 15 10 5 0 45 40 35 30 25 20 15 10 5 0 − 0.16 − 0.14 − 0.13 − 0.11 − 0.09 − 0.08 − 0.06 − 0.04 − 0.03 − 0.01 0.01 0.02 0.04 0.06 0.07 0.09 0.11 0.12 0.14 More Delta Gain (dB) Delta Gain (dB) 5 VCA2619 www.ti.com SBOS276A − AUGUST 2003 − REVISED AUGUST 2003 TYPICAL CHARACTERISTICS (continued) At TA = 25°C and VDD = 5V, load resistance = 500Ω on each output to ground, differential output (2VPP) MGS = 111, and fIN = 5MHz, unless otherwise noted. GAIN vs FREQUENCY (VCACNTL = 2.9V) 50 45 40 35 Gain (dB) Gain (dB) 30 25 20 15 10 5 0 100k 1M 10M 100M MGS = 010 MGS = 100 MGS = 111 40 30 20 10 0 − 10 − 20 100k 50 GAIN vs FREQUENCY (MGS = 111) VCACNTL = 2.9V VCACNTL = 1.9V VCACNTL = 0.9V 1M 10M 100M Frequency (MHz) Frequency (MHz) OUTPUT REFERRED NOISE vs VCACNTL 1100 1000 900 800 Noise (nV/√ Hz) Noise (nV/√ Hz) 700 600 500 400 300 200 100 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 INPUT REFERRED NOISE vs VCACNTL 1500 1400 1300 1200 1100 1000 900 800 700 600 500 400 300 200 100 0 RS = 50Ω RS= 50Ω MGS = 111 MGS = 111 MGS = 100 MGS = 100 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 VCACNTL (V) VCACNTL (V) NOISE FIGURE vs RS 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 10 100 RS (Ω ) 1k 100 INPUT REFERRED NOISE vs RS 10 1 1 10 RS (Ω ) 100 1k 6 Noise Figure (dB) Noise (nV√ Hz) VCA2619 www.ti.com SBOS276A − AUGUST 2003 − REVISED AUGUST 2003 TYPICAL CHARACTERISTICS (continued) At TA = 25°C and VDD = 5V, load resistance = 500Ω on each output to ground, differential output (2VPP) MGS = 111, and fIN = 5MHz, unless otherwise noted. 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0 NOISE FIGURE vs VCACNTL − 30 − 35 Harmonic Distortion (dBc) − 40 − 45 − 50 − 55 − 60 − 65 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 HARMONIC DISTORTION vs FREQUENCY (Differential, 2VPP, MGS = 010) VCA CN TL = 0.9V, H2 VCA CN TL = 0.9V, H3 VCA CN TL = 2.9V, H2 VCA CN TL = 2.9V, H3 Noise Figure (dB) VCACNTL (V) − 70 100k 1M Frequency (Hz) 10M − 30 − 35 − 40 − 45 − 50 − 55 − 60 − 65 − 70 − 75 − 80 − 85 − 90 100k HARMONIC DISTORTION vs FREQUENCY (Differential, 2VPP, MGS = 100) − 30 − 35 Harmonic Distortion (dBc) − 40 − 45 − 50 − 55 − 60 − 65 − 70 − 75 − 80 100k HARMONIC DISTORTION vs FREQUENCY (Differential, 2VPP, MGS = 111) VCA C NTL VCA C NTL VCA C NTL VCA C NTL = = = = 0.9V, H2 0.9V, H3 2.9V, H2 2.9V, H3 Harmonic Distortion (dBc) VCA CN T L = 0.9V, H2 VCA CN T L = 0.9V, H3 VCA CN T L = 2.9V, H2 VCA CN T L = 2.9V, H3 1M Frequency (Hz) 10M 1M Frequency (Hz) 10M − 30 − 35 Harmonic Distortion (dBc) − 40 − 45 − 50 − 55 − 60 − 65 − 70 − 75 − 80 − 85 − 90 100k HARMONIC DISTORTION vs FREQUENCY (Single− Ended, 1VPP, MGS = 010) − 30 − 35 Harmonic Distortion (dBc) − 40 − 45 − 50 − 55 − 60 − 65 − 70 − 75 − 80 − 85 − 90 100k HARMONIC DISTORTION vs FREQUENCY (Single− Ended, 1VPP, MGS = 100) VCA CN TL = 0.9V, H2 VCA CN TL = 0.9V, H3 VCA CN TL = 2.9V, H2 VCA CN TL = 2.9V, H3 VCA CN TL = 0.9V, H2 VCA CN TL = 0.9V, H3 VCA CN TL = 2.9V, H2 VCA CN TL = 2.9V, H3 1M Frequency (Hz) 10M 1M Frequency (Hz) 10M 7 VCA2619 www.ti.com SBOS276A − AUGUST 2003 − REVISED AUGUST 2003 TYPICAL CHARACTERISTICS (continued) At TA = 25°C and VDD = 5V, load resistance = 500Ω on each output to ground, differential output (2VPP) MGS = 111, and fIN = 5MHz, unless otherwise noted. − 30 − 35 Harmonic Distortion (dBc) − 40 − 45 − 50 − 55 − 60 − 65 − 70 − 75 − 80 − 85 − 90 100k HARMONIC DISTORTION vs FREQUENCY (Single− Ended, 1VPP, MGS = 111) VCA C NTL = 0.9V, H2 VCA C NTL = 0.9V, H3 VCA C NTL = 2.9V, H2 VCA C NTL = 2.9V, H3 0 −5 − 10 − 15 − 20 − 25 − 30 − 35 − 40 − 45 − 50 − 55 − 60 − 65 − 70 − 75 − 80 0.9 1.1 HARMONIC DISTORTION vs VCACNTL (Differential, 2VPP, 5MHz) MGS = 010, H2 MGS = 100, H2 MGS = 111, H2 MGS = 010, H3 MGS = 100, H3 MGS = 111, H3 Harmonic Distortion (dBc) 1M Frequency (Hz) HARMONIC DISTORTION vs VCACNTL (Single− Ended, 1VPP, 5MHz) MGS = 010, MGS = 100, MGS = 111, MGS = 010, MGS = 100, MGS = 111, 10M 1.3 1.5 1.7 1.9 2.1 2.3 2.5 2.7 2.9 VCACNTL (V) INTERMODULATION DISTORTION (Single− Ended, 1VPP , f IN = 10MHz) H2 H2 H2 H3 H3 H3 0 − 10 − 20 Amplitude (dB) 2.9 − 30 − 35 Harmonic Distortion (dBc) − 40 − 45 − 50 − 55 − 60 − 65 0.9 1.1 − 30 − 40 − 50 − 60 − 70 − 80 − 90 − 100 1.3 1.5 1.7 1.9 2.1 2.3 2.5 2.7 9.5 9.6 9.7 9.8 VCACNTL (V) INTERMODULATION DISTORTION (Differential, 2 VPP, fIN = 10MHz) 0 − 10 − 20 − 40 − 50 − 60 − 70 − 80 − 90 − 100 9.5 9.6 9.7 9.8 9.9 10.0 10.1 10.2 10.3 10.4 10.5 Frequency (MHz) Cross Talk (dB) Amplitude (dB) − 30 0 − 10 − 20 − 30 − 40 − 50 − 60 − 70 1M 9.9 10.0 10.1 10.2 10.3 10.4 10.5 Frequency (MHz) CROSS TALK vs FREQUENCY (Differential, 2VPP, MGS = 011) VCACNTL = 0.9V VCACNTL = 1.9V VCACNTL = 2.9V 10M Frequency (Hz) 20M 8 VCA2619 www.ti.com SBOS276A − AUGUST 2003 − REVISED AUGUST 2003 TYPICAL CHARACTERISTICS (continued) At TA = 25°C and VDD = 5V, load resistance = 500Ω on each output to ground, differential output (2VPP) MGS = 111, and fIN = 5MHz, unless otherwise noted. OVERLOAD DISTORTION vs FREQUENCY 0 2nd− Harmonic Distortion (dBc) − 10 − 20 − 30 − 40 − 50 − 60 1M 10M 55 0.2V 0.3V 0.5V 1V ICC (mA) 54 53 52 51 50 49 48 47 46 45 ICC (CHA and CHB) vs TEMPERATURE − 40 − 30 − 20 − 10 0 10 20 30 40 50 60 70 80 90 Frequency (Hz) Temperature (_ C) OVERVIEW The VCA2619 is a dual-channel, VGA consisting of three primary blocks: an Input Buffer, a VCA, and a PGA. All stages are ac coupled, with the coupling into the PGA stage being made variable by placing an external capacitor between the CP1 and CP2 pins. This will be discussed further in the PGA section. By using the internal coupling into the PGA, the result is a high-pass filter characteristic with cutoff at approximately 75kHz. The output PGA naturally rolls off at around 30MHz, making the usable bandwidth of the VCA2619 between 75kHz and 30MHz. INPUT BUFFER The input buffer is a unity gain amplifier (gain of +1) with a bandwidth of 100MHz with an input resistance of approximately 600kΩ. The input buffer isolates the circuit driving the VCA2619 inputs from the internal VCA block, which would present a varying impedance to the input circuitry. To allow symmetrical operation of the input buffer, the input to the buffer must be ac coupled through an external capacitor. The recommended value of the capacitor is 0.01µF. It should be noted that if the capacitor value were increased, the power-on time of the VCA2619 would be increased. If a decrease in the power-on time is needed, the value can be decreased to no less than 100pF. Channel A Input Buffer VCA PGA Channel A Output VCA Control Analog Control Maximum Gain Select MGS Channel B Input Buffer VCA PGA Channel B Output Figure 1. Simplified Block Diagram of the VCA2619. 9 VCA2619 www.ti.com SBOS276A − AUGUST 2003 − REVISED AUGUST 2003 VOLTAGE-CONTROLLED ATTENUATOR The magnitude of the VCA input signal from the input buffer is reduced by a programmable attenuation factor, set by the analog VCA Control Voltage (VCACNTL) at pin 24. The maximum attenuation is programmable by using the three MGS bits (pins 21, 22, and 23). Figure 2 illustrates this dual-adjust characteristic. 0 VCA Attenuation (dB) Minimum Attenuation The MGS bits adjust the overall range of attenuation and maximum gain while the VCACNTL voltage adjusts the actual attenuation factor. Figure 3 is a simplified version of the voltage control attenuator. Figure 4 illustrates the piecewise approximation to the logarithmic control characteristics. At any given maximum gain setting, the analog variable gain characteristic is linear in dB as a function of the control voltage, and is created as a piecewise approximation of an ideal dB-linear transfer function. The VCA control circuitry is common to both channels of the VCA2619. The range for the VCACNTL input spans from 0V to 3V. Although overdriving the VCA CNTL input above the recommended 3V maximum will not damage the part, this condition should be avoided. − 41 − 52.3 0 Maximum Attenuation 3.0V Control Voltage Figure 2. Swept Attenuator Characteristic. RS Input Q1A VCM Q1B Q2A Q2B Q3A Q3B Q4A Q4B Q5A Q5B Output A1 B1 B2 A2 A3 A4 A5 Figure 3. Simplified Attenuator Diagram. 10 VCA2619 www.ti.com SBOS276A − AUGUST 2003 − REVISED AUGUST 2003 Attenuator Input RS A1 to A10 Attenuator Stages QS Q1 Q2 A2 C1 C2 V2 V3 A3 C3 V4 Q3 A4 C4 V5 Q4 A5 C5 V6 Q5 A6 C6 V7 Q6 A7 C7 V8 Q7 A8 C8 V9 Q8 A9 C9 Q9 A10 Attenuator Output Q10 VCM A1 C10 V10 V1 Control Input C1 to C10 Clipping Amplifiers 0dB −5.2dB Attenuation Characteristic of Individual FETs VCM − VT 0 V1 V2 V3 V4 V5 V6 V7 V8 V9 V10 Characteristic of Attenuator Control Stage Output OVERALL CONTROL CHARACTERISTICS OF ATTENUATOR 0dB −52.3dB 0.2V Control Signal 3V Figure 4. Piecewise Approximation to Logarithmic Control Characteristics. 11 VCA2619 www.ti.com SBOS276A − AUGUST 2003 − REVISED AUGUST 2003 PGA POST-AMPLIFIER Figure 5 shows a simplified circuit diagram of the PGA block. As stated before, the input to the PGA is ac coupled with an internal capacitor. Provisions are made so that an external capacitor can be placed in parallel with the internal capacitor, thus lowering the usable low-frequency bandwidth. The low-frequency bandwidth is set by the following equation: MGS SETTING 000 001 010 011 100 101 110 111 Table 1. MGS Settings. ATTENUATOR GAIN VCACNTL = 0.2V TO 3V Not Valid Not Valid −41.0dB to 0dB −43.3dB to 0dB −46.4dB to 0dB −48.2dB to 0dB −50.2dB to 0dB −52.3dB to 0dB ATTENUATOR + DIFFERENTIAL PGA GAIN Not Valid Not Valid −12dB to 29dB −11.5dB to 31.8dB −11.5dB to 34.9dB −10.6dB to 37.6dB −9.8dB to 40.4dB −9.3dB to 43.3dB 1 (2 @ p @ 500kW @ (220pF ) C EXTERNAL)) (1) where CEXTERNAL is the external capacitor value in farads. Care should be taken to avoid using too large a value of capacitor, as this can increase the power-on delay time. The PGA gain is programmed with the same MGS bits that control the VCA maximum attenuation factor. For VCACNTL = 3V (no attenuation), the VCA + PGA gain will be controlled by the programmed PGA gain (29dB to 43dB in approximately 3dB steps). For clarity, the gain and attenuation factors are detailed in Table I. The PGA architecture converts the single−ended signal from the VCA into a differential signal. Low input noise was also a requirement of the PGA design due to the large amount of signal attenuation that can be asserted before the PGA. At minimum VCA attenuation (used for small input signals), the input buffer noise dominates; at maximum VCA attenuation (large input signals), the PGA noise dominates. Note that if the PGA output is single−ended, the apparent gain will be 6dB lower. VDD To Bias Circuitry RL Q1 Q11 Q12 Q9 RL VCAOUTP VCM Q3 RS1 RS2 +In Q4 Q2 Q5 Q14 Q13 Q8 VCM VCAOUTN Q7 Q10 Q6 − In To Bias Circuitry Figure 5. Simplified Block Diagram of PGA. 12 VCA2619 www.ti.com SBOS276A − AUGUST 2003 − REVISED AUGUST 2003 LAYOUT CONSIDERATIONS The VCA2619 is an analog amplifier capable of high gain. When working on a PCB layout for the VCA2619, it is recommended to utilize a solid ground plane that is connected to analog ground. This helps to maximize the noise performance of the VCA2619. Adequate power−supply decoupling must be used in order to achieve the best possible performance. Decoupling capacitors on the VCACNTL voltage should also be used to help minimize noise. Recommended values can be obtained from the layout diagram of Figure 6. +5V 0.1µF 1µF +5V 0.1µF 0.1µF 1µF 1µF 0.01µF INA 1 INA 28 3 5 VDDA VDDR VCM 25 −OUTA +OUTA 26 0.01µF − OUTA 0.01µF +OUTA VCA2619 − OUTB 0.01µF INB 8 INB VDDB VBIAS VCNTL 1µF 0.1µF +5V 1µF 13 4 24 +OUTB 16 15 0.01µF − OUTB 0.01µF +OUTB 0.1µF 0.1µF VCACNTL Figure 6. VCA2619 Layout. 13 PACKAGE OPTION ADDENDUM www.ti.com 9-Dec-2004 PACKAGING INFORMATION Orderable Device VCA2619YR VCA2619YT (1) Status (1) ACTIVE ACTIVE Package Type TQFP TQFP Package Drawing PBS PBS Pins Package Eco Plan (2) Qty 32 32 2000 250 None None Lead/Ball Finish Call TI Call TI MSL Peak Temp (3) Call TI Call TI The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) Eco Plan - May not be currently available - please check http://www.ti.com/productcontent for the latest availability information and additional product content details. None: Not yet available Lead (Pb-Free). Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes. Green (RoHS & no Sb/Br): TI defines "Green" to mean "Pb-Free" and in addition, uses package materials that do not contain halogens, including bromine (Br) or antimony (Sb) above 0.1% of total product weight. (3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDECindustry standard classifications, and peak solder temperature. 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Addendum-Page 1 MECHANICAL DATA MPQF027 – NOVEMBER 1995 PBS (S-PQFP-G32) 0,23 0,17 24 17 PLASTIC QUAD FLATPACK 0,50 0,08 M 25 16 32 9 0,13 NOM 1 3,50 TYP 5,05 SQ 4,95 7,10 SQ 6,90 1,05 0,95 8 Gage Plane 0,25 0,10 MIN 0,70 0,40 0°– 7° Seating Plane 1,20 MAX 0,08 4087735/A 11/95 NOTES: A. All linear dimensions are in millimeters. B. This drawing is subject to change without notice. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 1 IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. All products are sold subject to TI’s terms and conditions of sale supplied at the time of order acknowledgment. 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