www.ti.com THS4211 THS4215 SLOS400D – SEPTEMBER 2002 – REVISED NOVEMBER 2004 LOW-DISTORTION, HIGH-SPEED, VOLTAGE FEEDBACK AMPLIFIER FEATURES • • • • • • • • • DESCRIPTION Unity Gain Stability Wide Bandwidth: 1 GHz High Slew Rate: 970 V/µs Low Distortion – –90 dBc THD at 30 MHz – 130 MHz Bandwidth (0.1 dB, G = 2) – 0.007% Differential Gain – 0.003° Differential Phase High Output Drive, IO = 200 mA Excellent Video Performance – 130 MHz Bandwidth (0.1 dB, G = 2) – 0.007% Differential Gain – 0.003° Differential Phase Supply Voltages – +5 V, ±5 V, +12 V, +15 V Power Down Functionality (THS4215) Evaluation Module Available The THS4211 and THS4215 are high slew rate, unity gain stable voltage feedback amplifiers designed to run from supply voltages as low as 5 V and as high as 15 V. The THS4215 offers the same performance as the THS4211 with the addition of power-down capability. The combination of high slew rate, wide bandwidth, low distortion, and unity gain stability make the THS4211 and THS4215 high performance devices across multiple ac specifications. Designers using the THS4211 are rewarded with higher dynamic range over a wider frequency band without the stability concerns of decompensated amplifiers. The devices are available in SOIC, MSOP with PowerPAD™, and leadless MSOP with PowerPAD packages. THS4211 NC ININ+ VS- 1 8 2 7 3 6 4 5 NC VS+ VOUT NC APPLICATIONS • • • • • High Linearity ADC Preamplifier Differential to Single-Ended Conversion DAC Output Buffer Active Filtering Video Applications RELATED DEVICES DEVICE DESCRIPTION THS4271 1.4 GHz voltage feedback amplifier THS4503 Wideband fully differential amplifier THS3202 Dual, wideband current feedback amplifier Low-Distortion, Wideband Application Circuit HARMONIC DISTORTION vs FREQUENCY +5 V 50 Ω Source -50 50 Ω 49.9 Ω THS4211 _ -5 V 392 Ω 392 Ω NOTE: Power supply decoupling capacitors not shown VO Harmonic Distortion - dBc VI Gain = 2 Rf = 392 Ω RL = 150 Ω VO = 2 VPP VS = ±5 V -55 + -60 -65 -70 -75 -80 HD2 -85 HD3 -90 -95 -100 1 10 f - Frequency - MHz 100 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. PowerPAD is a trademark of Texas Instruments. PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. Copyright © 2002–2004, Texas Instruments Incorporated THS4211 THS4215 www.ti.com SLOS400D – SEPTEMBER 2002 – REVISED NOVEMBER 2004 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. ABSOLUTE MAXIMUM RATINGS over operating free-air temperature range (unless otherwise noted) (1) UNIT Supply voltage, VS 16.5 V ±VS Input voltage, VI Output current, IO 100 mA Continuous power dissipation Maximum junction temperature, TJ See Dissipation Rating Table (2) 150°C Maximum junction temperature, continuous operation, long term reliability TJ (3) 125°C Storage temperature range, Tstg –65°C to 150°C Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds ESD ratings (1) (2) (3) 300°C HBM 4000 V CDM 1500 V MM 200 V Stresses above these ratings may cause permanent damage. Exposure to absolute maximum conditions for extended periods may degrade device reliability. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those specified is not implied. The absolute maximum ratings under any condition is limited by the constraints of the silicon process. Stresses above these ratings may cause permanent damage. Exposure to absolute maximum conditions for extended periods may degrade device reliability. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those specified is not implied. The maximum junction temperature for continuous operation is limited by package constraints. Operation above this temperature may result in reduced reliability and/or lifetime of the device. PACKAGE DISSIPATION RATINGS (1) (1) (2) (3) (3) PACKAGE θJC (°C/W) θJA (2) (°C/W) TA≤ 25°C TA= 85°C POWER RATING D (8 pin) 38.3 97.5 1.02 W 410 mW DGN (8 pin) (1) 4.7 58.4 1.71 W 685 mW DGK (8 pin) 54.2 260 385 mW 154 mW DRB (8 pin) 5 45.8 2.18 W 873 mW The THS4211/5 may incorporate a PowerPAD™ on the underside of the chip. This acts as a heat sink and must be connected to a thermally dissipative plane for proper power dissipation. Failure to do so may result in exceeding the maximum junction temperature which could permanently damage the device. See TI technical briefs SLMA002 and SLMA004 for more information about utilizing the PowerPAD thermally enhanced package. This data was taken using the JEDEC standard High-K test PCB. Power rating is determined with a junction temperature of 125°C. This is the point where distortion starts to substantially increase. Thermal management of the final PCB should strive to keep the junction temperature at or below 125°C for best performance and long term reliability. RECOMMENDED OPERATING CONDITIONS Supply voltage, (VS+ and VS–) Input common-mode voltage range 2 Dual supply Single supply MIN MAX ±2.5 ±7.5 5 15 VS–+ 1.2 VS+ – 1.2 UNIT V V THS4211 THS4215 www.ti.com SLOS400D – SEPTEMBER 2002 – REVISED NOVEMBER 2004 PACKAGING/ORDERING INFORMATION PACKAGED DEVICES PACKAGE TYPE PACKAGE MARKING SOIC-8 — MSOP-8 BEJ QFN-8-PP (1) BET MSOP-8-PP (1) BFN SOIC-8 — MSOP-8 BEZ QFN-8-PP (1) BEU MSOP-8-PP (1) BFQ TRANSPORT MEDIA, QUANTITY Non-power-down THS4211D THS4211DR THS4211DGK THS4211DGKR THS4211DRBT THS4211DRBR THS4211DGN THS4211DGNR Rails, 75 Tape and Reel, 2500 Rails, 100 Tape and Reel, 2500 Tape and Reel, 250 Tape and Reel, 3000 Rails, 80 Tape and Reel, 2500 Power-down THS4215D THS4215DR THS4215DGK THS4215DGKR THS4215DRBT THS4215DRBR THS4215DGN THS4215DGNR (1) Rails, 75 Tape and Reel, 2500 Rails, 100 Tape and Reel, 2500 Tape and Reel, 250 Tape and Reel, 3000 Rails, 80 Tape and Reel, 2500 The PowerPAD is electrically isolated from all other pins. PIN ASSIGNMENTS (TOP VIEW) D, DRB, DGK, DGN THS4211 NC 1 8 NC IN- 2 7 IN+ 3 VS- 4 NC = No Connetion (TOP VIEW) D, DRB, DGK, DGN THS4215 REF 1 8 PD VS+ IN- 2 7 VS+ 6 VOUT IN+ 3 6 VOUT 5 NC VS- 4 5 NC NC = No Connection See Note A. NOTE A: The devices with the power down option defaults to the ON state if no signal is applied to the PD pin. 3 THS4211 THS4215 www.ti.com SLOS400D – SEPTEMBER 2002 – REVISED NOVEMBER 2004 ELECTRICAL CHARACTERISTICS, VS = ±5 V RF = 392 Ω, RL = 499 Ω, G = +2, unless otherwise noted TYP OVER TEMPERATURE UNITS MIN/ TYP/ MAX 1 GHz Typ G = –1, POUT = –16 dBm 325 MHz Typ G = 2, POUT = –16 dBm 325 MHz Typ G = 5, POUT = –16 dBm 70 MHz Typ PARAMETER TEST CONDITIONS 25°C 25°C 0°C to –40°C 70°C to 85°C AC PERFORMANCE G = 1, POUT = –7 dBm Small signal bandwidth G = 10, POUT = –16 dBm 35 MHz Typ 0.1 dB flat bandwidth G = 1, POUT = –7 dBm 70 MHz Typ Gain bandwidth product G > 10 , f = 1 MHz 350 MHz Typ Full-power bandwidth G = –1, VO = 2 Vp 77 MHz Typ G = 1, VO = 2 V Step 970 V/µs Typ G = –1, VO = 2 V Step 850 V/µs Typ 22 ns Typ 55 ns Typ –78 dBc Typ RL = 499 Ω –90 dBc Typ RL = 150Ω –100 dBc Typ RL = 499 Ω –100 dBc Typ RL = 150 Ω –68 dBc Typ RL = 499 Ω –70 dBc Typ RL = 150Ω –80 dBc Typ RL = 499 Ω Slew rate Settling time to 0.1% Settling time to 0.01% G = –1, VO = 4 V Step Harmonic distortion RL = 150 Ω 2nd-order harmonic distortion G = 1, VO = 1 VPP, f = 30 MHz 3rd-order harmonic distortion Harmonic distortion 2nd-order harmonic distortion G = 2, VO = 2 VPP, f = 30 MHz 3rd-order harmonic distortion –82 dBc Typ 3rd-order intermodulation (IMD3) G = 2, VO = 2 VPP, RL = 150 Ω, f = 70 MHz –53 dBc Typ 3rd-order output intercept (OIP3) G = 2, VO = 2 VPP, RL = 150 Ω, f = 70 MHz 32 dBm Typ 0.007 % Typ 0.003 ° Typ Differential gain (NTSC, PAL) Differential phase (NTSC, PAL) G = 2, RL = 150 Ω Input voltage noise f = 1 MHz 7 nV/√Hz Typ Input current noise f = 10 MHz 4 pA√Hz Typ VO = ±0.3 V, RL = 499 Ω 70 65 62 60 dB Min 3 12 14 14 mV Max ±40 ±40 µV/°C Typ 7 15 18 20 µA Max ±10 ±10 nA/°C Typ DC PERFORMANCE Open-loop voltage gain (AOL) Input offset voltage Average offset voltage drift Input bias current Average bias current drift Input offset current Average offset current drift 4 VCM = 0 V 0.3 6 7 8 µA Max ±10 ±10 nA/°C Typ THS4211 THS4215 www.ti.com SLOS400D – SEPTEMBER 2002 – REVISED NOVEMBER 2004 TYP PARAMETER TEST CONDITIONS OVER TEMPERATURE 25°C 25°C 0°C to –40°C 70°C to 85°C UNITS MIN/ TYP/ MAX Min INPUT CHARACTERISTICS ±4 ±3.8 ±3.7 ±3.6 V Common-mode rejection ratio VCM = ± 1 V 56 52 50 48 dB Min Input resistance Common-mode 4 MΩ Typ Input capacitance Common-mode/differential 0.3/0.2 pF Typ Common-mode input range OUTPUT CHARACTERISTICS Output voltage swing Output current (sourcing) Output current (sinking) Output impedance RL = 10 Ω f = 1 MHz ±4.0 ±3.8 ±3.7 ±3.6 V Min 220 200 190 180 mA Min 170 140 130 120 mA Min Ω Typ 0.3 POWER SUPPLY Specified operating voltage ±5 ±7.5 ±7.5 ±7.5 V Max Maximum quiescent current 19 22 23 24 mA Max Minimum quiescent current 19 16 15 14 mA Min Power supply rejection (+PSRR) VS+ = 5.5 V to 4.5 V, VS– = 5 V 64 58 54 54 dB Min Power supply rejection (–PSRR) VS+ = 5 V, VS– = –5.5 V to –4.5 V 65 60 56 56 dB Min POWER-DOWN CHARACTERISTICS (THS4215 ONLY) REF = 0 V, or VS– Power-down voltage level REF = VS+ or Floating Power-down quiescent current Enable Power-down Enable Power-down REF+1.8 V Min REF+1 V Max REF–1 V Min REF–1.5 V Max PD = Ref +1.0 V, Ref = 0 V 650 850 900 1000 µA Max PD = Ref –1.5 V, Ref = 5 V 450 650 800 900 µA Max µs Typ Turnon time delay(t(ON)) 50% of final supply current value 4 Turnoff time delay (t(Off)) 50% of final supply current value 3 µs Typ 4 GΩ Typ 250 kΩ Typ Input impedance Output impedance f = 1 MHz 5 THS4211 THS4215 www.ti.com SLOS400D – SEPTEMBER 2002 – REVISED NOVEMBER 2004 ELECTRICAL CHARACTERISTICS, VS = 5 V RF = 392 Ω, RL = 499 Ω, G = +2, unless otherwise noted PARAMETER TEST CONDITIONS TYP OVER TEMPERATURE 25°C 0°C to –40°C 70°C to 85°C 25°C UNITS MIN/ TYP/ MAX AC PERFORMANCE Small signal bandwidth G = 1, POUT = –7 dBm 980 MHz Typ G = –1, POUT = –16 dBm 300 MHz Typ G = 2, POUT = –16 dBm 300 MHz Typ MHz Typ G = 5, POUT = –16 dBm 65 G = 10, POUT = –16 dBm 30 MHz Typ 0.1 dB flat bandwidth G = 1, POUT = –7 dBm 90 MHz Typ Gain bandwidth product G > 10, f = 1 MHz 300 MHz Typ Full-power bandwidth G = –1, VO = 2 Vp 64 MHz Typ G = 1, VO = 2 V Step 800 V/µs Typ G = –1, VO = 2 V Step 750 V/µs Typ 22 ns Typ 84 ns Typ RL = 150 Ω –60 dBc Typ RL = 499 Ω –60 dBc Typ RL = 150 Ω –68 dBc Typ RL = 499 Ω –68 dBc Typ –70 dBc Typ Slew rate Settling time to 0.1% Settling time to 0.01% G = –1, VO = 2 V Step Harmonic distortion 2nd-order harmonic distortion G = 1, VO = 1 VPP, f = 30 MHz 3rd-order harmonic distortion 3rd-order intermodulation (IMD3) 3rd-order output intercept (OIP3) G = 1, VO = 1 VPP, RL = 150 Ω , f = 70 MHz 34 dBm Typ Input-voltage noise f = 1 MHz 7 nV/√Hz Typ Input-current noise f = 10 MHz 4 pA/√Hz Typ VO = ± 0.3 V, RL = 499 Ω 68 63 60 60 dB Min 3 12 14 14 mV Max ±40 ±40 µV/°C Typ 7 15 17 18 µA Max ±10 ±10 nA/°C Typ 0.3 6 7 8 µA Max ±10 ±10 nA/°C Typ V Min DC PERFORMANCE Open-loop voltage gain (AOL) Input offset voltage Average offset voltage drift Input bias current Average bias current drift VCM = VS/2 Input offset current Average offset current drift INPUT CHARACTERISTICS Common-mode input range 1/4 1.2/3.8 1.3/3.7 1.4/3.6 50 48 45 Common-mode rejection ratio VCM = ± 0.5 V, VO = 2.5 V 54 dB Min Input resistance Common-mode 4 MΩ Typ Input capacitance Common-mode/differential 0.3/0.2 pF Typ OUTPUT CHARACTERISTICS Output voltage swing 1/4 1.2/3.8 1.3/3.7 1.4/3.6 V Min Output current (sourcing) 230 210 190 180 mA Min 150 120 100 90 mA Min Ω Typ Output current (sinking) Output impedance 6 RL = 10 Ω f = 1 MHz 0.3 THS4211 THS4215 www.ti.com SLOS400D – SEPTEMBER 2002 – REVISED NOVEMBER 2004 TYP OVER TEMPERATURE 25°C 25°C 0°C to –40°C 70°C to 85°C Specified operating voltage 5 15 15 Maximum quiescent current 19 22 23 Minimum quiescent current 19 16 PARAMETER TEST CONDITIONS UNITS MIN/ TYP/ MAX 15 V Max 24 mA Max 15 14 mA Min POWER SUPPLY Power supply rejection (+PSRR) VS+ = 5.5 V to 4.5 V, VS– = 0 V 63 58 54 54 dB Min Power supply rejection (–PSRR) VS+ = 5 V, VS– = –0.5 V to 0.5 V 65 60 56 56 dB Min POWER-DOWN CHARACTERISTICS (THS4215 ONLY) REF = 0 V, or VS– Power-down voltage level REF = VS+ or floating Enable Power down Enable Power down REF+1.8 V Min REF+1 V Max REF–1 V Min REF–1.5 V Max Power-down quiescent current PD = Ref +1.0 V, Ref = 0 V 450 650 750 850 µA Max Power-down quiescent current PD = Ref –1.5 V, Ref = 5 V 400 650 750 850 µA Max 4 µs Typ 3 µns Typ 6 GΩ Typ 75 kΩ Typ Turnon-time delay(t(ON)) Turnoff-time delay (t(Off)) 50% of final value Input impedance Output impedance f = 1 MHz 7 THS4211 THS4215 SLOS400D – SEPTEMBER 2002 – REVISED NOVEMBER 2004 www.ti.com TYPICAL CHARACTERISTICS Table of Graphs (±5 V) FIGURE Small-signal unity gain frequency response 1 Small-signal frequency response 2 0.1 dB gain flatness frequency response 3 Large-signal frequency response 4 Slew rate vs Output voltage Harmonic distortion vs Frequency Harmonic distortion vs Output voltage swing 3rd-order intermodulation distortion vs Frequency 14, 16 3rd-order output intercept point vs Frequency 15, 17 Voltage and current noise vs Frequency 18 Differential gain vs Number of loads 19 Differential phase vs Number of loads 20 Settling time 5 6, 7, 8, 9 10, 11, 12, 13 21 Quiescent current vs supply voltage 22 Output voltage vs Load resistance 23 Frequency response vs Capacitive load 24 Open-loop gain and phase vs Frequency 25 Open-loop gain vs Case temperature 26 Rejection ratios vs Frequency 27 Rejection ratios vs Case temperature 28 Common-mode rejection ratio vs Input common-mode range 29 Input offset voltage vs Case temperature 30 Input bias and offset current vs Case temperature 31 Small signal transient response 32 Large signal transient response 33 Overdrive recovery 34 Closed-loop output impedance vs Frequency 35 Power-down quiescent current vs Supply voltage 36 Power-down output impedance vs Frequency 37 Turnon and turnoff delay times 8 38 THS4211 THS4215 www.ti.com SLOS400D – SEPTEMBER 2002 – REVISED NOVEMBER 2004 Table of Graphs (5 V) FIGURE Small-signal unity gain frequency response 39 Small-signal frequency response 40 0.1 dB gain flatness frequency response 41 Large signal frequency response 42 Slew rate vs Output voltage Harmonic distortion vs Frequency 44, 45, 46, 47 Harmonic distortion vs Output voltage swing 48, 49, 50, 51 3rd-order intermodulation distortion vs Frequency 52, 54 3rd-order vs Frequency 53, 55 vs Frequency 56 intercept point Voltage and current noise Settling time 43 57 Quiescent current vs Supply voltage 58 Output voltage vs Load resistance 59 Frequency response vs Capacitive load 60 Open-loop gain and phase vs Frequency 61 Open-loop gain vs Case temperature 62 Rejection ratios vs Frequency 63 Rejection ratios vs Case temperature 64 Common-mode rejection ratio vs Input common-mode range 65 Input offset voltage vs Case temperature 66 Input bias and offset current vs Case temperature 67 Small signal transient response 68 Large signal transient response 69 Overdrive recovery 70 Closed-loop output impedance vs Frequency 71 Power-down quiescent current vs Supply voltage 72 Power-down output impedance vs Frequency 73 Turnon and turnoff delay times 74 9 THS4211 THS4215 www.ti.com SLOS400D – SEPTEMBER 2002 – REVISED NOVEMBER 2004 TYPICAL CHARACTERISTICS (±5 V Graphs) SMALL SIGNAL UNITY GAIN FREQUENCY RESPONSE SMALL SIGNAL FREQUENCY RESPONSE 22 Gain = 1 RL = 499 Ω VO = 250 mV VS = ±5 V 3 0.1 20 2 1 0 -1 -2 0 Gain = 10 18 Small Signal Gain - dB 4 -0.1 16 Small Signal Gain - dB 5 Small Signal Gain - dB 0.1 dB GAIN FLATNESS FREQUENCY RESPONSE Gain = 5 14 RL = 499 Ω Rf = 392 Ω VO = 250 mV VS = ±5 V 12 10 8 6 Gain = 2 4 2 -4 100 k 1M 10 M 100 M 1G Gain = -1 -2 -4 100 k 1M 10 G f - Frequency - Hz 10 M 100 M f - Frequency - Hz SLEW RATE vs OUTPUT VOLTAGE HARMONIC DISTORTION vs FREQUENCY Gain = 1 RL = 499 Ω VO = 2 VPP VS = ±5 V 1M Fall, Gain = 1 1000 800 Fall, Gain =- 1 Rise, Gain = -1 600 400 RL = 499 Ω Rf = 392 Ω VS = ±5 V 200 10 M 100 M 0 f - Frequency - Hz -75 HD2, RL = 150 Ω -80 HD2, RL = 499 Ω -85 -90 -95 0.5 1 1.5 2 2.5 3 3.5 4 4.5 1 5 10 Figure 5. Figure 6. HARMONIC DISTORTION vs FREQUENCY HARMONIC DISTORTION vs FREQUENCY HARMONIC DISTORTION vs FREQUENCY -50 -55 Gain = 1 VO = 2 VPP VS = ±5 V HD3, RL = 150 Ω and RL = 499 Ω Gain = 2 Rf = 392 Ω VO = 1 VPP VS = ±5 V -60 -65 HD2, RL = 499 Ω HD2, RL = 150 Ω -80 -85 -90 -65 -70 HD3, RL = 150Ω, and RL = 499 Ω -75 -80 HD2, RL = 499Ω -85 HD2, RL = 150Ω -90 -60 -65 -70 HD2, RL = 499Ω -75 -90 -95 -100 -100 Figure 7. 10 f - Frequency - MHz Figure 8. 100 HD3, RL = 150Ω, and RL = 499 Ω -85 -100 1 HD2, RL = 150Ω -80 -95 100 Gain = 2 Rf = 392 Ω VO = 2 VPP VS = ±5 V -55 -95 10 100 f - Frequency - MHz VO - Output Voltage - V Harmonic Distortion - dBc Harmonic Distortion - dBc HD3, RL = 150 Ω and RL = 499 Ω Figure 4. f - Frequency - MHz 10 -70 -100 0 1G Gain = 1 VO = 1 VPP VS = ±5 V -65 Harmonic Distortion - dBc -4 100 k 1G -60 Harmonic Distortion - dBc SR - Slew Rate - V/ µ s Large Signal Gain - dB -2 1 10 M 100 M f - Frequency - Hz LARGE SIGNAL FREQUENCY RESPONSE -1 -75 Gain = 1 RL = 499 Ω VO = 250 mV VS = ±5 V Figure 3. 0 -70 -0.7 Figure 2. 1200 -60 -0.6 -1 1M 1G Rise, Gain = 1 -55 -0.5 -0.9 1400 -50 -0.4 Figure 1. 1 -3 -0.3 -0.8 0 -3 -0.2 1 10 f - Frequency - MHz Figure 9. 100 THS4211 THS4215 www.ti.com SLOS400D – SEPTEMBER 2002 – REVISED NOVEMBER 2004 TYPICAL CHARACTERISTICS (±5 V Graphs) (continued) HARMONIC DISTORTION vs OUTPUT VOLTAGE SWING HD2, RL = 150Ω -85 -90 HD2, RL = 499Ω -95 -60 -65 HD2, RL = 499Ω -70 HD2, RL = 150Ω -75 -80 -85 -90 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 HD3, RL = 499Ω -100 0 2.5 3 3.5 4 4.5 5 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 VO - Output Voltage Swing - ±V HARMONIC DISTORTION vs OUTPUT VOLTAGE SWING THIRD ORDER INTERMODULATION DISTORTION vs FREQUENCY THIRD ORDER OUTPUT INTERCEPT POINT vs FREQUENCY HD3, RL = 499Ω -70 -75 -80 HD2, RL = 150Ω -85 -90 -95 -100 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 60 -45 Third-Order Output Intersept Point - dBm HD3, RL = 150Ω HD2, RL = 499Ω 0 1.5 2 Figure 12. -60 -65 0.5 1 Figure 11. Third-Order Intermodulation Distortion - dBc -55 HD2, RL = 150Ω -90 Figure 10. Gain = 2 Rf = 249 Ω f = 32 MHz VS = ±5 V -50 Gain = 1 RL = 150 Ω VS = ±5 V 200 kHz Tone Spacing -50 -55 -60 -65 -70 VO = 2 VPP -75 -80 -85 -90 -95 -100 VO = 1 VPP 10 Gain = 1 RL = 150 Ω VS = ±5 V 200 kHz Tone Spacing 55 50 45 VO = 1 VPP 40 VO = 2 VPP 35 30 0 100 VO - Output Voltage Swing - ±V 20 40 60 80 100 f - Frequency - MHz f - Frequency - MHz Figure 13. Figure 14. Figure 15. THIRD ORDER INTERMODULATION DISTORTION vs FREQUENCY THIRD ORDER OUTPUT INTERCEPT POINT vs FREQUENCY VOLTAGE AND CURRENT NOISE vs FREQUENCY 100 -55 -60 -65 -70 VO = 2 VPP -75 -80 -85 -90 VO = 1 VPP -95 -100 10 100 f - Frequency - MHz Figure 16. 55 50 45 VO = 1 VPP 40 100 Hz Gain = 2 RL = 150 Ω VS = ±5 V 200 kHz Tone Spacing Hz -50 Third-Order Output Intersept Point - dBm 60 Gain = 2 RL = 150 Ω VS = ±5 V 200 kHz Tone Spacing -45 Vn 10 35 VO = 2 VPP 30 10 In I n - Current Noise - pA/ -40 nV/ Harmonic Distortion - dBc -85 VO - Output Voltage Swing - ±V -40 -45 HD3, RL = 150Ω -80 -100 0 HD2, RL = 499Ω HD3, RL = 499Ω VO - Output Voltage Swing - ±V Third-Order Intermodulation Distortion - dBc -75 -95 -95 -100 Gain = 2 Rf = 249 Ω f = 8 MHz VS = ±5 V -70 HD3, RL = 150Ω Harmonic Distortion - dBc HD3, RL = 150Ω HD3, RL = 499Ω -80 -65 Gain = 1 f= 32 MHz VS = ±5 V -55 Vn - Voltage Noise - Harmonic Distortion - dBc -75 HARMONIC DISTORTION vs OUTPUT VOLTAGE SWING -50 Gain = 1 f= 8 MHz VS = ±5 V Harmonic Distortion - dBc -70 HARMONIC DISTORTION vs OUTPUT VOLTAGE SWING 25 1 20 0 20 40 60 f - Frequency - MHz Figure 17. 80 100 1k 10 k 100 k 1M 10 M 1 100 M f - Frequency - Hz Figure 18. 11 THS4211 THS4215 www.ti.com SLOS400D – SEPTEMBER 2002 – REVISED NOVEMBER 2004 TYPICAL CHARACTERISTICS (±5 V Graphs) (continued) DIFFERENTIAL GAIN vs NUMBER OF LOADS DIFFERENTIAL PHASE vs NUMBER OF LOADS 0.030 0.015 ° Differential Phase - 0.020 Gain = 2 Rf = 392 Ω VS = ±5 V 40 IRE - NTSC and Pal Worst Case ±100 IRE Ramp 0.18 PAL NTSC 0.010 0.16 0.14 2 VO - Output Voltage - V Gain = 2 Rf = 392 Ω VS = ±5 V 40 IRE - NTSC and Pal Worst Case ±100 IRE Ramp 0.025 Differential Gain - % SETTLING TIME 3 0.20 0.12 0.10 PAL 0.08 0.06 NTSC 0.04 0.005 Rising Edge 1 -1 Gain = -1 RL = 499 Ω Rf = 392 Ω f= 1 MHz VS = ±5 V -2 Falling Edge 0 0.02 0 0 1 2 3 4 5 6 7 8 0 3 4 5 6 7 -3 8 15 20 QUIESCENT CURRENT vs SUPPLY VOLTAGE OUTPUT VOLTAGE vs LOAD RESISTANCE FREQUENCY RESPONSE vs CAPACITIVE LOAD TA = 85°C TA = 25°C VO - Output Voltage - V TA = -40°C 16 5 1 4 0.5 3 14 2 1 TA = -40 to 85°C 0 -1 -2 3 3.5 4 4.5 10 5 VS =±5 V R(ISO) = 10 Ω CL = 100 pF 0 -0.5 R(ISO) = 15 Ω CL = 50 pF -1 -1.5 R(ISO) = 25 Ω CL = 10 pF -2 -2.5 -5 2.5 100 -3 100 k 1000 RL - Load Resistance - Ω VS - Supply Voltage - ±V 1M 10 M 100 M Figure 23. Figure 24. OPEN-LOOP GAIN AND PHASE vs FREQUENCY OPEN-LOOP GAIN vs CASE TEMPERATURE REJECTION RATIOS vs FREQUENCY 90 180 70 160 TA = 25°C 140 50 120 40 100 30 80 20 60 10 40 0 20 Open-Loop Gain - dB 60 Phase - ° 85 1M 10 M 100 M f - Frequency - Hz Figure 25. 0 1G PSRR- TA = 85°C 80 75 TA = -40°C 70 65 100 k VS = ±5 V 60 Rejection Ratios - dB VS = ±5 V 70 1G Capacitive Load - Hz Figure 22. 80 25 -3 -4 10 Open-Loop Gain - dB 10 t - Time - ns Figure 21. 12 12 5 Figure 20. 18 -10 10 k 0 Figure 19. 22 Quiescent Current - mA 2 Number of Loads - 150 Ω Number of Loads - 150 Ω 20 1 Normalized Gain - dB 0 50 CMRR 40 30 PSRR+ 20 10 60 2.5 3 3.5 4 Case Temperature - °C Figure 26. 4.5 5 0 100 k 1M 10 M f - Frequency - Hz Figure 27. 100 M 1G THS4211 THS4215 www.ti.com SLOS400D – SEPTEMBER 2002 – REVISED NOVEMBER 2004 TYPICAL CHARACTERISTICS (±5 V Graphs) (continued) REJECTION RATIOS vs CASE TEMPERATURE COMMON-MODE REJECTION RATIO vs INPUT COMMON-MODE RANGE PSRR- CMMR PSRR+ 40 30 20 10 0 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 8 50 45 40 35 30 25 20 15 10 VS = ±5 V TA = 25°C 5 0 -4.5 -3 Case Temperature - °C 1 0 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 4.5 TC - Case Temperature - °C LARGE SIGNAL TRANSIENT RESPONSE 0.65 0.6 0.55 IIB- 0.5 IOS 0.45 0.4 0.35 IIB+ 5.8 0.3 5.7 0.25 VO - Output Voltage - V 0.7 VS = ±5 V I OS - Input Offset Current - µ A I IB - Input Bias Current - µ A 2 SMALL SIGNAL TRANSIENT RESPONSE 0.12 0.1 1.5 0.08 1 0.06 0.04 0.02 0 -0.02 Gain = -1 RL = 499 Ω Rf =392 Ω tr/tf = 300 ps VS = ±5 V -0.04 -0.06 -0.08 -0.1 0.2 -40 -30 -20-10 0 10 20 30 40 50 60 70 80 90 0.5 0 Gain = -1 RL = 499 Ω Rf = 392 Ω tr/tf = 300 ps VS = ±5 V -0.5 -1 -1.5 -0.12 -1 TC - Case Temperature - °C 0 1 2 3 4 5 6 t - Time - ns 7 8 9 -2 10 0 2 4 6 8 10 12 14 16 18 20 t - Time - ns Figure 31. Figure 32. Figure 33. OVERDRIVE RECOVERY CLOSED-LOOP OUTPUT IMPEDANCE vs FREQUENCY POWER-DOWN QUIESCENT CURRENT vs SUPPLY VOLTAGE 100 k 2.5 4 2 3 1.5 2 1 1 0.5 0 0 -1 -0.5 -2 -1 -3 -1.5 -4 -2 -5 -2.5 -6 -3 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 t - Time - µs Figure 34. 1 Closed-Loop Output Impedance - Ω 3 VS = ±5 V VI - Input Voltage - V Single-Ended Output Voltage - V 3 INPUT BIAS AND OFFSET CURRENT vs CASE TEMPERATURE 6 6 5 VS = 5 V 4 Figure 30. 6.1 5.6 3 5 Figure 29. 6.2 5.9 1.5 VS = ±5 V 6 Figure 28. 6.4 6.3 0 7 Input Common-Mode Range - V 6.6 6.5 -1.5 VO - Output Voltage - V 50 9 55 10 k 1k 800 RL = 499 Ω, RF = 392 Ω, PIN = -4 dBm VS = ±5 V Power-Down Quiescent Current - µ A Rejection Ratios - dB 60 60 VOS - Input Offset Voltage - mV VS = ±5 V 70 CMRR - Common-Mode Rejection Ratio - dB 80 INPUT OFFSET VOLTAGE vs CASE TEMPERATURE 100 10 1 0.1 0.01 100 k TA = 85°C 700 600 500 TA = 25°C 400 TA = -40°C 300 200 100 0 1M 10 M 100 M f - Frequency - Hz Figure 35. 1G 2.5 3 3.5 4 4.5 VS - Supply Voltage - ±V 5 Figure 36. 13 THS4211 THS4215 www.ti.com SLOS400D – SEPTEMBER 2002 – REVISED NOVEMBER 2004 TYPICAL CHARACTERISTICS (±5 V Graphs) (continued) POWER-DOWN OUTPUT IMPEDANCE vs FREQUENCY 1000 0.1 1M 10 M 100 M f - Frequency - Hz Figure 37. 14 1G 4.5 0.03 10 0.001 100 k 6 0.035 VO - Output Voltage Level - V Power-Down Output Impedance - Ω 0.04 Gain = 1 RL = 499 Ω PIN = -1 dBm VS = ±5 V 10 G 3 1.5 0.025 0.02 0 0.015 Gain = -1 RL = 499 Ω VS = ±5 V 0.01 -3 -4.5 0.005 -6 0 -0.005 -0.01 -1.5 -7.5 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 t - Time - ns Figure 38. V I - Input Voltage Level - V TURNON AND TURNOFF TIMES DELAY TIME THS4211 THS4215 www.ti.com SLOS400D – SEPTEMBER 2002 – REVISED NOVEMBER 2004 TYPICAL CHARACTERISTICS (5 V Graphs) SMALL SIGNAL UNITY GAIN FREQUENCY RESPONSE SMALL SIGNAL FREQUENCY RESPONSE 22 Gain = 1 RL = 499 Ω VO = 250 mV VS = 5 V 2 0 -1 -2 10 M 100 M 1G 16 Gain = 5 14 RL = 499 Ω Rf = 392 Ω VO = 250 mV VS = 5 V 12 10 8 6 Gain = 2 4 2 0 Gain = -1 -2 -4 100 k 1M -3 1M 10 G f - Frequency - Hz -0.9 -1 10 M 100 M f - Frequency - Hz 1G 1M Rise, G = 1 Harmonic Distortion - dBc SR - Slew Rate - V/ µ s 800 700 600 Rise, G = -1 500 Fall, G = -1 400 300 RL = 499 Ω Rf = 392 Ω VS = 5 V 100 100 M 1G -60 -65 -70 HD2 -75 -80 HD3 -85 -90 -95 -100 0 10 M Gain = 1 VO = 1 VPP RL = 150 Ω, and 499 Ω VS = 5 V -55 200 1M 0.4 0.6 0.8 1 1.2 1.4 1.6 VO - Output Voltage -V 1.8 1 2 10 f - Frequency - MHz Figure 42. Figure 43. Figure 44. HARMONIC DISTORTION vs FREQUENCY HARMONIC DISTORTION vs FREQUENCY HARMONIC DISTORTION vs FREQUENCY Harmonic Distortion - dBc Gain = 1 VO = 2 VPP RL = 150 Ω, and 499 Ω VS = 5 V HD3 -65 HD2 -70 -75 -80 -40 -30 -50 -40 -60 HD2 -70 HD3 -80 Gain = 2 VO = 1 VPP Rf = 392 Ω RL = 150 Ω and 499 Ω VS = 5 V -90 -85 -100 -90 10 f - Frequency - MHz Figure 45. 100 Harmonic Distortion - dBc -40 1G -50 Fall, G = 1 f - Frequency - Hz 1 10 M 100 M f - Frequency - Hz HARMONIC DISTORTION vs FREQUENCY Gain = 1 RL = 499 Ω VO = 2 VPP VS = 5 V -60 Gain = 1 RL = 499 Ω VO = 250 mV VS = 5 V -0.7 SLEW RATE vs OUTPUT VOLTAGE -2 -55 -0.6 LARGE SIGNAL FREQUENCY RESPONSE -1 -50 -0.5 Figure 41. 0 -45 -0.4 Figure 40. 900 -4 100 K -0.3 -0.8 1000 -3 -0.2 Figure 39. 1 Large Signal Gain - dB 0 -0.1 Gain = 10 18 1 -4 100 k 0.1 20 Small Signal Gain - dB Small Signal Gain - dB 3 Small Signal Gain - dB 4 Harmonic Distortion - dBc 0.1 dB GAIN FLATNESS FREQUENCY RESPONSE 1 10 f - Frequency - MHz Figure 46. 100 -50 100 HD2 HD3 -60 -70 Gain = 2 VO = 2 VPP Rf = 392 Ω RL = 150 Ω and 499 Ω VS = 5 V -80 -90 1 10 f - Frequency - MHz 100 Figure 47. 15 THS4211 THS4215 www.ti.com SLOS400D – SEPTEMBER 2002 – REVISED NOVEMBER 2004 TYPICAL CHARACTERISTICS (5 V Graphs) (continued) HARMONIC DISTORTION vs OUTPUT VOLTAGE SWING -45 -50 -65 -50 -55 -70 -75 HD3 -80 -85 Gain = 1 RL = 150 Ω, and 499 Ω, f = 8 MHz VS = 5 V -90 -100 HD2 -60 -65 HD3 -70 -75 Gain = 1 RL = 150 Ω, and 499 Ω, f = 32 MHz VS = 5 V -80 -85 -90 0.5 1 1.5 2 VO - Output Voltage Swing - V 2.5 -75 -80 Gain = 2 Rf = 392 Ω RL = 150 Ω and 499 Ω f = 8 MHz VS = 5 V -85 -90 -95 -100 0 2.5 0.5 1 1.5 2 2.5 VO - Output Voltage Swing - V Figure 50. HARMONIC DISTORTION vs OUTPUT VOLTAGE SWING THIRD ORDER INTERMODULATION DISTORTION vs FREQUENCY THIRD ORDER OUTPUT INTERCEPT POINT vs FREQUENCY -50 -55 HD3 -60 -65 Gain = 2 Rf = 392 Ω RL = 150 Ω and 499 Ω f = 32 MHz VS = 5 V -70 -75 -80 0.5 1 1.5 2 2.5 -40 50 Gain = 1 RL = 150 Ω VS = 5 V 200 kHz Tone Spacing -45 -50 -55 -60 -65 VO = 2VPP -70 -75 -80 -85 VO = 1VPP -90 -95 -100 10 Gain = 1 RL = 150 Ω VS = 5 V 200 kHz Tone Spacing 45 VO = 1VPP 40 VO = 2VPP 35 30 0 100 VO - Output Voltage Swing - V 10 20 30 40 50 60 70 80 f - Frequency - MHz f - Frequency - MHz Figure 51. Figure 52. Figure 53. THIRD ORDER INTERMODULATION DISTORTION vs FREQUENCY THIRD ORDER OUTPUT INTERCEPT POINT vs FREQUENCY VOLTAGE AND CURRENT NOISE vs FREQUENCY 100 -60 VO = 2 VPP -70 -80 VO = 1 VPP -90 -100 10 100 f - Frequency - MHz Figure 54. 40 35 Hz VO = 1 VPP 30 100 nV/ -50 45 Vn - Voltage Noise - -40 Gain = 2 RL = 150 Ω VS = 5 V 200 kHz Tone Spacing Hz 50 Gain = 1 RL = 150 Ω VS = 5 V 200 kHz Tone Spacing Vn 10 VO = 2 VPP 25 20 10 In 15 1 10 0 20 40 60 f - Frequency - MHz Figure 55. 80 100 1k 10 k 100 k 1M f - Frequency - Hz Figure 56. 10 M 1 100 M I n - Current Noise - pA/ -30 Third-Order Output Intersept Point - dBm Third-Order Intermodulation Distortion - dBc HD3 -70 Figure 49. HD2 0 0.5 1 1.5 2 VO - Output Voltage Swing - V -65 Figure 48. -40 -45 0 HD2 -60 Third-Order Output Intersept Point - dBm 0 Harmonic Distortion - dBc -55 Harmonic Distortion - dBc Harmonic Distortion - dBc HD2 -95 16 HARMONIC DISTORTION vs OUTPUT VOLTAGE SWING -60 Third-Order Intermodulation Distortion - dBc Harmonic Distortion - dBc HARMONIC DISTORTION vs FREQUENCY THS4211 THS4215 www.ti.com SLOS400D – SEPTEMBER 2002 – REVISED NOVEMBER 2004 TYPICAL CHARACTERISTICS (5 V Graphs) (continued) QUIESCENT CURRENT vs SUPPLY VOLTAGE SETTLING TIME 1.5 OUTPUT VOLTAGE vs LOAD RESISTANCE 2 22 Rising Edge Gain = -1 RL = 499 Ω Rf = 392 Ω f= 1 MHz VS = 5 V 0 -0.5 18 TA = -40°C 16 14 Falling Edge -1 VO - Output Voltage - V 0.5 TA = 25°C Quiescent Current - mA VO - Output Voltage - V TA = 85°C 20 1 1.5 1 0.5 TA = -40 to 85°C 0 -0.5 -1 12 -1.5 10 -1.5 5 10 15 t - Time - ns 20 -3 100 k 100 RL - Load Resistance - Ω 1000 OPEN-LOOP GAIN AND PHASE vs FREQUENCY OPEN-LOOP GAIN vs CASSE TEMPERATURE 80 R(ISO) = 25 Ω, CL = 10 pF 90 180 VS = 5 V 70 160 TA = 25°C R(ISO) = 15 Ω CL = 50 pF R(ISO) = 10 Ω CL = 100 pF 140 50 120 40 100 30 80 20 60 10 40 0 20 Open-Loop Gain - dB 85 60 TA = 85°C 80 75 TA = -40°C 70 65 VS = 5 V 1M 10 M 100 M 1G -10 10 k 100 k 1M 10 M 100 M 60 0 1G 2.5 3 3.5 4 4.5 5 Case Temperature - °C f - Frequency - Hz Figure 60. Figure 61. Figure 62. REJECTION RATIOS vs FREQUENCY REJECTION RATIOS vs CASE TEMPERATURE COMMON-MODE REJECTION RATIO vs INPUT COMMON-MODE RANGE 80 70 VS = 5 V VS = 5 V Rejection Ratios - dB 50 CMRR 40 30 PSRR+ 20 PSRR- 70 PSRR- 60 Rejection Ratios - dB 10 FREQUENCY RESPONSE vs CAPACITIVE LOAD Capacitive Load - Hz 10 0 100 k 5 Figure 59. -2 -2.5 4.5 60 50 PSRR+ CMMR 40 30 20 10 1M 10 M f - Frequency - Hz Figure 63. 100 M 1G 0 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 Case Temperature - °C Figure 64. CMRR - Common-Mode Rejection Ratio - dB -1.5 4 Figure 58. Open-Loop Gain - dB Normalized Gain - dB -1 3.5 Figure 57. 0 -0.5 3 VS - Supply Voltage - ±V 1 0.5 -2 2.5 25 Phase - ° 0 60 VS = 5 V 55 50 45 40 35 30 25 20 15 10 5 0 0 1 2 3 4 Input Common-Mode Voltage Range - V 5 Figure 65. 17 THS4211 THS4215 www.ti.com SLOS400D – SEPTEMBER 2002 – REVISED NOVEMBER 2004 TYPICAL CHARACTERISTICS (5 V Graphs) (continued) INPUT BIAS AND OFFSET CURRENT vs CASE TEMPERATURE VS = ±5 V 6 5 VS = 5 V 4 3 2 0.65 6.4 0.6 IIB- 6.3 0.55 6.2 0.5 6.1 0.45 IIB+ 6 0.4 5.9 0.35 IOS 5.8 0.3 5.7 1 0.12 0.1 Figure 66. LARGE SIGNAL TRANSIENT RESPONSE -1 -2 0 2 4 6 -1 1.5 1 1 0.5 0 0 -1 -0.5 -2 -1 100 k -1.5 0 7 8 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1k 10 100 10 1 0.1 0.01 100 k 1 9 1M 10 M 100 M f - Frequency - Hz 1G Figure 70. Figure 71. POWER-DOWN QUIESCENT CURRENT vs SUPPLY VOLTAGE POWER-DOWN OUTPUT IMPEDANCE vs FREQUENCY TURNON AND TURNOFF TIMES DELAY TIME 1000 TA = 85°C 600 500 TA = 25°C 400 TA = -40°C 300 200 100 3 3.5 4 4.5 VS - Supply Voltage - ±V Figure 72. 5 0.035 Gain = 1 RL = 499 Ω PIN = -1 dBm VS = 5 V 0.03 10 0.1 0.001 100 k 10 M 100 M f - Frequency - Hz Figure 73. 1G 3 10 G 1.5 0 0.02 0.015 -1.5 -3 0.01 Gain = -1 RL = 499 Ω VS = 5 V 0.005 0 -0.005 -0.01 1M 4.5 0.025 VO - Output Voltage Level - V Power-Down Output Impedance - Ω Power-Down Quiescent Current - µ A 3 4 5 6 t - Time - ns Figure 69. 0 18 2 RL = 499 Ω, RF = 392 Ω, PIN = -4 dBm VS = 5 V 10 k t - Time - µs 800 2.5 1 OVERDRIVE RECOVERY 2 8 10 12 14 16 18 20 0 CLOSED-LOOP OUTPUT IMPEDANCE vs FREQUENCY t - Time - ns 700 -0.06 Figure 68. -3 -1.5 Gain = -1 RL = 499 Ω Rf =392 Ω tr/tf = 300 ps VS = 5 V -0.04 -0.1 VI - Input Voltage - V Single-Ended Output Voltage - V VO - Output Voltage - V Gain = -1 RL = 499 Ω Rf = 392 Ω tr/tf = 300 ps VS = 5 V -0.02 -0.12 VS = 5 V -0.5 0.02 0 Figure 67. 3 1.5 0 0.04 TC - Case Temperature - °C TC - Case Temperature - °C 0.5 0.06 -0.08 0.25 0.2 5.6 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 0 -40 -30-20 -10 0 10 20 30 40 50 60 70 80 90 1 0.08 Closed-Loop Output Impedance - Ω 7 0.7 VS = 5 V 0 -4.5 -6 -7.5 0.01 0.02 0.03 0.04 0.05 0.06 0.07 t - Time - ns Figure 74. V I - Input Voltage Level - V 6.5 VO - Output Voltage - V 6.6 8 SMALL SIGNAL TRANSIENT RESPONSE I OS - Input Offset Current - µ A 9 I IB - Input Bias Current - µ A VOS - Input Offset Voltage - mV INPUT OFFSET VOLTAGE vs CASE TEMPERATURE THS4211 THS4215 www.ti.com SLOS400D – SEPTEMBER 2002 – REVISED NOVEMBER 2004 APPLICATION INFORMATION HIGH-SPEED OPERATIONAL AMPLIFIERS The THS4211 and the THS4215 operational amplifiers set new performance levels, combining low distortion, high slew rates, low noise, and a unity-gain bandwidth in excess of 1 GHz. To achieve the full performance of the amplifier, careful attention must be paid to printed-circuit board layout and component selection. The THS4215 provides a power-down mode, providing the ability to save power when the amplifier is inactive. A reference pin is provided to allow the user the flexibility to control the threshold levels of the power-down control pin. Applications Section Contents • • • • • • • • • • • • • • • • • • Wideband, Noninverting Operation Wideband, Inverting Gain Operation Single Supply Operation Saving Power With Power-Down Functionality and Setting Threshold Levels With the Reference Pin Power Supply Decoupling Techniques and Recommendations Using the THS4211 as a DAC Output Buffer Driving an ADC With the THS4211 Active Filtering With the THS4211 Building a Low-Noise Receiver With the THS4211 Linearity: Definitions, Terminology, Circuit Techniques and Design Tradeoffs An Abbreviated Analysis of Noise in Amplifiers Driving Capacitive Loads Printed-Circuit Board Layout Techniques for Optimal Performance Power Dissipation and Thermal Considerations Performance vs Package Options Evaluation Fixtures, Spice Models, and Applications Support Additional Reference Material Mechanical Package Drawings WIDEBAND, NONINVERTING OPERATION The THS4211 and the THS4215 are unity-gain, stable 1-GHz voltage-feedback operational amplifiers, with and without power-down capability, designed to operate from a single 5-V to 15-V power supply. with measurement equipment presenting a 50-Ω load impedance. In Figure 75, the 49.9-Ω shunt resistor at the VIN terminal matches the source impedance of the test generator. The total 499-Ω load at the output, combined with the 784-Ω total feedback-network load, presents the THS4211 and THS4215 with an effective output load of 305 Ω for the circuit shown in Figure 75. Voltage-feedback amplifiers, unlike current-feedback designs, can use a wide range of resistors values to set their gain with minimal impact on their stability and frequency response. Larger-valued resistors decrease the loading effect of the feedback network on the output of the amplifier, but this enhancement comes at the expense of additional noise and potentially lower bandwidth. Feedback-resistor values between 392 Ω and 1 kΩ are recommended for most applications. 5 V +V S + 100 pF 50 Ω Source 0.1 µF 6.8 µF + VI VO THS4211 49.9 Ω _ Rf 392 Ω 499 Ω 392 Ω Rg 0.1 µF 6.8 µF 100 pF -5 V + -VS Figure 75. Wideband, Noninverting Gain Configuration WIDEBAND, INVERTING GAIN OPERATION Since the THS4211 and THS4215 are general-purpose, wideband voltage-feedback amplifiers, several familiar operational-amplifier applications circuits are available to the designer. Figure 76 shows a typical inverting configuration where the input and output impedances and noise gain from Figure 75 are retained in an inverting circuit configuration. Inverting operation is a common requirement and offers several performance benefits. The inverting configuration shows improved slew rates and distortion due to the pseudo-static voltage maintained on the inverting input. Figure 75 shows the noninverting-gain configuration of 2 V/V used to demonstrate the typical performance curves. Most of the curves were characterized using signal sources with 50-Ω source impedances, and 19 THS4211 THS4215 www.ti.com SLOS400D – SEPTEMBER 2002 – REVISED NOVEMBER 2004 5 V +V S + 100 pF 0.1 µF 6.8 µF + RT 200 Ω CT 0.1 µF VO THS4211 _ 499 Ω 50 Ω Source VI Rg Rf 392 Ω RM 57.6 Ω 392 Ω 0.1 µF 100 pF -5 V 6.8 µF + -VS Figure 76. Wideband, Inverting Gain Configuration In the inverting configuration, some key design considerations must be noted. One is that the gain resistor (Rg) becomes part of the signal-channel input impedance. If input impedance matching is desired (beneficial when the signal is coupled through a cable, twisted pair, long PC board trace, or other transmission line conductor), Rg may be set equal to the required termination value and Rf adjusted to give the desired gain. However, care must be taken when dealing with low inverting gains, as the resultant feedback resistor value can present a significant load to the amplifier output. For an inverting gain of 2, setting Rg to 49.9 Ω for input matching eliminates the need for RM but requires a 100-Ω feedback resistor. This has the advantage that the noise gain becomes equal to 2 for a 50-Ω source impedance—the same as the noninverting circuit in Figure 75. However, the amplifier output now sees the 100-Ω feedback resistor in parallel with the external load. To eliminate this excessive loading, it is preferable to increase both Rg and Rf, values, as shown in Figure 76, and then achieve the input matching impedance with a third resistor (RM) to ground. The total input impedance becomes the parallel combination of Rg and RM. The next major consideration is that the signal source impedance becomes part of the noise gain equation and hence influences the bandwidth. For example, the RM value combines in parallel with the external 50-Ω source impedance (at high frequencies), yielding an effective source impedance of 50 Ω || 57.6 Ω = 26.8 Ω. This impedance is then added in series with Rg for calculating the noise gain. The result is 1.9 for Figure 76, as opposed to the 1.8 if RM is eliminated. The bandwidth is lower for the inverting gain-of-2 circuit in Figure 76 (NG=+1.9), than for the noninverting gain of 2 circuit in Figure 75. 20 The last major consideration in inverting amplifier design is setting the bias-current cancellation resistor on the noninverting input. If the resistance is set equal to the total dc resistance looking out of the inverting terminal, the output dc error, due to the input bias currents, is reduced to (input offset current) × Rf in Figure 76, the dc source impedance looking out of the inverting terminal is 392 Ω || (392 Ω + 26.8 Ω) = 200 Ω. To reduce the additional high-frequency noise introduced by the resistor at the noninverting input, and power-supply feedback, RT is bypassed with a capacitor to ground. SINGLE SUPPLY OPERATION The THS4211 is designed to operate from a single 5-V to 15-V power supply. When operating from a single power supply, care must be taken to ensure the input signal and amplifier are biased appropriately to maximize output voltage swing. The circuits shown in Figure 77 demonstrate methods to configure an amplifier for single-supply operation. +VS 50 Ω Source + VI 49.9 Ω RT THS4211 VO _ 499 Ω +VS Rf 2 Rg 392 Ω 392 Ω +VS 2 Rf 392 Ω VS 50 Ω Source Rg VI 57.6 Ω _ 392 Ω RT +VS +VS 2 2 THS4211 + VO 499 Ω Figure 77. DC-Coupled Single Supply Operation Saving Power With Power-Down Functionality and Setting Threshold Levels With the Reference Pin The THS4215 features a power-down pin (PD) which lowers the quiescent current from 19-mA down to 650-µA, ideal for reducing system power. The power-down pin of the amplifiers defaults to the positive supply voltage in the absence of an applied voltage, putting the amplifier in the power-on mode of operation. To conserve power, the amplifier is turned off by driving the power-down pin towards the nega- THS4211 THS4215 www.ti.com SLOS400D – SEPTEMBER 2002 – REVISED NOVEMBER 2004 tive rail. The threshold voltages for power-on and power-down are relative to the supply rails, and are given in the specification tables. Above the Enable Threshold Voltage, the device is on. Below the Disable Threshold Voltage, the device is off. Behavior between these threshold voltages is not specified. Note that this power-down functionality is just that; the amplifier consumes less power in power-down mode. The power-down mode is not intended to provide a high- impedance output. In other words, the power-down functionality is not intended to allow use as a 3-state bus driver. When in power-down mode, the impedance looking back into the output of the amplifier is dominated by the feedback and gain setting resistors, but the output impedance of the device itself varies depending on the voltage applied to the outputs. The time delays associated with turning the device on and off are specified as the time it takes for the amplifier to reach 50% of the nominal quiescent current. The time delays are on the order of microseconds because the amplifier moves in and out of the linear mode of operation in these transitions. Power-Down Reference Pin Operation In addition to the power-down pin, the THS4215 also features a reference pin (REF) which allows the user to control the enable or disable power-down voltage levels applied to the PD pin. Operation of the reference pin as it relates to the power-down pin is described below. In most split-supply applications, the reference pin will be connected to ground. In some cases, the user may want to connect it to the negative or positive supply rail. In either case, the user needs to be aware of the voltage level thresholds that apply to the power-down pin. The table below illustrates the relationship between the reference voltage and the power-down thresholds. REFERENCE VOLTAGE POWER-DOWN PIN VOLTAGE DEVICE DISABLED DEVICE ENABLED VS– to 0.5 (VS– + VS+) ≤ Ref + 1.0 V ≥ Ref + 1.8 V 0.5 (VS– + VS+) to VS+ ≤ Ref – 1.5 V ≥ Ref – 1 V The recommended mode of operation is to tie the reference pin to mid-rail, thus setting the threshold levels to mid-rail +1.0 V and midrail +1.8 V. NO. OF CHANNELS PACKAGES Single (8-pin) THS4215D, THS4215DGN, and THS4215DRB Power Supply Decoupling Techniques and Recommendations Power supply decoupling is a critical aspect of any high-performance amplifier design process. Careful decoupling provides higher quality ac performance (most notably improved distortion performance). The following guidelines ensure the highest level of performance. 1. Place decoupling capacitors as close to the power supply inputs as possible, with the goal of minimizing the inductance of the path from ground to the power supply. 2. Placement priority should put the smallest valued capacitors closest to the device. 3. Use of solid power and ground planes is recommended to reduce the inductance along power supply return current paths, with the exception of the areas underneath the input and output pins. 4. Recommended values for power supply decoupling include a bulk decoupling capacitor (6.8 to 22 µF), a mid-range decoupling capacitor (0.1 µF) and a high frequency decoupling capacitor (1000 pF) for each supply. A 100 pF capacitor can be used across the supplies as well for extremely high frequency return currents, but often is not required. APPLICATION CIRCUITS Driving an Analog-to-Digital Converter With the THS4211 The THS4211 can be used to drive high-performance analog-to-digital converters. Two example circuits are presented below. The first circuit uses a wideband transformer to convert a single-ended input signal into a differential signal. The differential signal is then amplified and filtered by two THS4211 amplifiers. This circuit provides low intermodulation distortion, suppressed even-order distortion, 14 dB of voltage gain, a 50-Ω input impedance, and a single-pole filter at 100 MHz. For applications without signal content at dc, this method of driving ADCs can be very useful. Where dc information content is required, the THS4500 family of fully differential amplifiers may be applicable. 21 THS4211 THS4215 www.ti.com SLOS400D – SEPTEMBER 2002 – REVISED NOVEMBER 2004 converter. The first circuit performs a differential to single-ended conversion with the THS4211 configured as a difference amplifier. The difference amplifier can double as the termination mechanism for the DAC outputs as well. 5V + VCM THS4211 _ 50 Ω (1:4 Ω) Source 1:2 196 Ω 3.3 V 3.3 V -5 V 392 Ω 24.9 Ω 100 Ω +5 V ADS5422 15 pF 14-Bit, 62 Msps 15 pF 196 Ω 392 Ω DAC5675 14-Bit, 400 MSps 24.9 Ω 392 Ω 100 Ω _ 196 Ω 49.9 Ω RF THS4211 + 392 Ω 392 Ω LO -5 V 392 Ω _ THS4211 + VCM Figure 78. A Linear, Low Noise, High Gain ADC Preamplifier The second circuit depicts single-ended ADC drive. While not recommended for optimum performance using converters with differential inputs, satisfactory performance can sometimes be achieved with single-ended input drive. An example circuit is shown here for reference. 50 Ω Source THS4211 + _ + RT RISO 100 Ω 0.1 µF THS4211 _ -5 V 16.5 Ω 68 pf IN Rf 392 Ω ADS807 100 Ω CF 1 nF IN 12-Bit, CM 53 Msps 1.82 kΩ Rg For cases where a differential signaling path is desirable, a pair of THS4211 amplifiers can be used as output buffers. The circuit depicts differential drive into a mixer's IF inputs, coupled with additional signal gain and filtering. 3.3 V 3.3 V +5 V VI 49.9 Ω Figure 80. Differential to Single-Ended Conversion of a High-Speed DAC Output 1 nF IF+ DAC5675 14-Bit, 400 MSps 392 Ω 100 Ω 392 Ω 392 Ω 49.9 Ω 392 Ω 49.9 Ω RF(out) 0.1 µF 392 Ω IF1 nF 1 nF _ NOTE: For best performance, high-speed ADCs should be driven differentially. See the THS4500 family of devices for more information. Figure 79. Driving an ADC With a Single-Ended Input CF + THS4211 Figure 81. Differential Mixer Drive Circuit Using the DAC5675 and the THS4211 Using the THS4211 as a DAC Output Buffer Active Filtering With the THS4211 Two example circuits are presented here showing the THS4211 buffering the output of a digital-to-analog High-frequency active filtering with the THS4211 is achievable due to the amplifier's high slew-rate, wide bandwidth, and voltage feedback architecture. Several options are available for high-pass, low-pass, bandpass, and bandstop filters of varying orders. A simple two-pole low pass filter is presented here as an example, with two poles at 100 MHz. 22 THS4211 THS4215 www.ti.com SLOS400D – SEPTEMBER 2002 – REVISED NOVEMBER 2004 100 Ω 3.9 pF + VI- 50 Ω Source 392 Ω Rf1 5V 57.6 Ω _ Rg1 49.9 Ω THS4211 VO + 33 pF _ -5 V Figure 82. A Two-Pole Active Filter With Two Poles Between 90 MHz and 100 MHz A Low-Noise Receiver With the THS4211 A combination of two THS4211 amplifiers can create a high-speed, low-distortion, low-noise differential receiver circuit as depicted in Figure 83. With both amplifiers operating in the noninverting mode of operation, the circuit presents a high load impedance to the source. The designer has the option of controlling the impedance through termination resistors if a matched termination impedance is desired. 100 Ω VI+ + 49.9 Ω VO+ _ 392 Ω 787 Ω 100 Ω 392 Ω _ VI- 100 Ω Rf2 _ 392 Ω VI Rg2 THS4211 49.9 Ω VO- + Figure 83. A High Input Impedance, Low Noise, Differential Receiver A modification on this circuit to include a difference amplifier turns this circuit into a high-speed instrumentation amplifier, as shown in Figure 84. 100 Ω _ Rf1 THS4211 + 49.9 Ω VO THS4211 Rg2 + 49.9 Ω Rf2 VI+ Figure 84. A High-Speed Instrumentation Amplifier 2R f1 V i–V i– R f2 VO 1 1 2 Rg1 Rg2 (1) THEORY AND GUIDELINES Distortion Performance The THS4211 provides excellent distortion performance into a 150-Ω load. Relative to alternative solutions, it provides exceptional performance into lighter loads, as well as exceptional performance on a single 5-V supply. Generally, until the fundamental signal reaches very high frequency or power levels, the 2nd harmonic dominates the total harmonic distortion with a negligible 3rd harmonic component. Focusing then on the 2nd harmonic, increasing the load impedance directly improves distortion. The total load includes the feedback network; in the noninverting configuration (Figure 75) this is the sum of Rf and Rg, while in the inverting configuration (Figure 76), only Rf needs to be included in parallel with the actual load. LINEARITY: DEFINITIONS, TERMINOLOGY, CIRCUIT TECHNIQUES, AND DESIGN TRADEOFFS The THS4211 features execllent distortion performance for monolithic operational amplifiers. This section focuses on the fundamentals of distortion, circuit techniques for reducing nonlinearity, and methods for equating distortion of operational amplifiers to desired linearity specifications in RF receiver chains. Amplifiers are generally thought of as linear devices. The output of an amplifier is a linearly-scaled version of the input signal applied to it. However, amplifier transfer functions are nonlinear. Minimizing amplifier nonlinearity is a primary design goal in many applications. 23 THS4211 THS4215 www.ti.com SLOS400D – SEPTEMBER 2002 – REVISED NOVEMBER 2004 Intercept points are specifications long used as key design criteria in the RF communications world as a metric for the intermodulation distortion performance of a device in the signal chain (e.g., amplifiers, mixers, etc.). Use of the intercept point, rather than strictly the intermodulation distortion, allows simpler system-level calculations. Intercept points, like noise figures, can be easily cascaded back and forth through a signal chain to determine the overall receiver chain's intermodulation distortion performance. The relationship between intermodulation distortion and intercept point is depicted in Figure 85 and Figure 86. PO PO Power ∆fc = fc - f1 ∆fc = f2 - fc IMD3 = PS - PO PS fc - 3∆f f2 However, with an operational amplifier, the output does not require termination as an RF amplifier would. Because closed-loop amplifiers deliver signals to their outputs regardless of the impedance present, it is important to comprehend this when evaluating the intercept point of an operational amplifier. The THS4211 yields optimum distortion performance when loaded with 150 Ω to 1 kΩ, very similar to the input impedance of an analog-to-digital converter over its input frequency band. As a result, terminating the input of the ADC to 50 Ω can actually be detrimental to system performance. The discontinuity between open-loop, class-A amplifiers and closed-loop, class-AB amplifiers becomes apparent when comparing the intercept points of the two types of devices. Equation 2 and Equation 3 define an intercept point, relative to the intermodulation distortion. IMD 3 OIP 3 P O where 2 (2) PS f1 fc Due to the intercept point's ease of use in system level calculations for receiver chains, it has become the specification of choice for guiding distortion-related design decisions. Traditionally, these systems use primarily class-A, single-ended RF amplifiers as gain blocks. These RF amplifiers are typically designed to operate in a 50-Ω environment. Giving intercept points in dBm implies an associated impedance (50 Ω ). fc + 3∆f f - Frequency - MHz Figure 85. P O 10 log POUT (dBm) 1X OIP3 V 2P 2RL 0.001 (3) NOTE: PO is the output power of a single tone, RL is the load resistance, and VP is the peak voltage for a single tone. NOISE ANALYSIS PO IMD3 IIP3 3X PS Figure 86. 24 PIN (dBm) High slew rate, unity-gain stable, voltage-feedback operational amplifiers usually achieve their slew rate at the expense of a higher input noise voltage. The 7 nV/√Hz input voltage noise for the THS4211 and THS4215 is, however, much lower than comparable amplifiers. The input-referred voltage noise, and the two input-referred current noise terms (4 pA/√Hz), combine to give low output noise under a wide variety of operating conditions. Figure 87 shows the amplifier noise analysis model with all the noise terms included. In this model, all noise terms are taken to be noise voltage or current density terms in either nV/√Hz or pA/√Hz. THS4211 THS4215 www.ti.com SLOS400D – SEPTEMBER 2002 – REVISED NOVEMBER 2004 The Typical Characteristics show the recommended isolation resistor vs capacitive load and the resulting frequency response at the load. Parasitic capacitive loads greater than 2 pF can begin to degrade the performance of the THS4211. Long PC board traces, unmatched cables, and connections to multiple devices can easily cause this value to be exceeded. Always consider this effect carefully, and add the recommended series resistor as close as possible to the THS4211 output pin (see Board Layout Guidelines). THS4211/THS4215 ENI + RS IBN ERS EO _ 4kTRS Rf Rg 4kT Rg ERF 4kTRf IBI 4kT = 1.6E-20J at 290K Figure 87. Noise Analysis Model The total output shot noise voltage can be computed as the square of all square output noise voltage contributors. Equation 4 shows the general form for the output noise voltage using the terms shown in Equation 4: EO 2 The criterion for setting this R(ISO) resistor is a maximum bandwidth, flat frequency response at the load. For a gain of +2, the frequency response at the output pin is already slightly peaked without the capacitive load, requiring relatively high values of R(ISO) to flatten the response at the load. Increasing the noise gain also reduces the peaking. FREQUENCY RESPONSE vs CAPACITIVE LOAD 2 ENI 2 IBNRS 4kTR S NG 2 IBIRf 4kTRfNG 1 Dividing this expression by the noise gain (NG=(1+ Rf/Rg)) gives the equivalent input-referred spot noise voltage at the noninverting input, as shown in Equation 5: 0 EO 2 2 E NI 2 I BNRS 4kTR S INGR 4kTR NG BI f f Normalized Gain - dB (4) 0.5 VS =±5 V R(ISO) = 10 Ω CL = 100 pF -0.5 R(ISO) = 15 Ω CL = 50 pF -1 -1.5 R(ISO) = 25 Ω CL = 10 pF -2 -2.5 (5) -3 100 k Driving Capacitive Loads One of the most demanding, and yet very common, load conditions for an op amp is capacitive loading. Often, the capacitive load is the input of an A/D converter, including additional external capacitance, which may be recommended to improve A/D linearity. A high-speed, high open-loop gain amplifier like the THS4211 can be very susceptible to decreased stability and closed-loop response peaking when a capacitive load is placed directly on the output pin. When the amplifier's open-loop output resistance is considered, this capacitive load introduces an additional pole in the signal path that can decrease the phase margin. When the primary considerations are frequency response flatness, pulse response fidelity, or distortion, the simplest and most effective solution is to isolate the capacitive load from the feedback loop by inserting a series isolation resistor between the amplifier output and the capacitive load. This does not eliminate the pole from the loop response, but rather shifts it and adds a zero at a higher frequency. The additional zero acts to cancel the phase lag from the capacitive load pole, thus increasing the phase margin and improving stability. 1M 10 M 100 M 1G Capacitive Load - Hz Figure 88. Isolation Resistor Diagram BOARD LAYOUT Achieving optimum performance with a high frequency amplifier like the THS4211 requires careful attention to board layout parasitics and external component types. Recommendations that optimize performance include the following: 1. Minimize parasitic capacitance to any ac ground for all of the signal I/O pins. Parasitic capacitance on the output and inverting input pins can cause instability: on the noninverting input, it can react with the source impedance to cause unintentional band limiting. To reduce unwanted capacitance, a window around the signal I/O pins should be opened in all of the ground and power planes around those pins. Otherwise, ground and power planes should be unbroken elsewhere on the board. 25 THS4211 THS4215 SLOS400D – SEPTEMBER 2002 – REVISED NOVEMBER 2004 2. Minimize the distance (< 0.25”) from the power supply pins to high frequency 0.1-µF decoupling capacitors. At the device pins, the ground and power plane layout should not be in close proximity to the signal I/O pins. Avoid narrow power and ground traces to minimize inductance between the pins and the decoupling capacitors. The power supply connections should always be decoupled with these capacitors. Larger (2.2-µF to 6.8-µF) decoupling capacitors, effective at lower frequency, should also be used on the main supply pins. These may be placed somewhat farther from the device and may be shared among several devices in the same area of the PC board. 3. Careful selection and placement of external components preserves the high frequency performance of the THS4211. Resistors should be a very low reactance type. Surface-mount resistors work best and allow a tighter overall layout. Metal-film and carbon composition, axially-leaded resistors can also provide good high frequency performance. Again, keep their leads and PC board trace length as short as possible. Never use wire-wound type resistors in a high frequency application. Since the output pin and inverting input pin are the most sensitive to parasitic capacitance, always position the feedback and series output resistor, if any, as close as possible to the output pin. Other network components, such as noninverting input-termination resistors, should also be placed close to the package. Where double-side component mounting is allowed, place the feedback resistor directly under the package on the other side of the board between the output and inverting input pins. Even with a low parasitic capacitance shunting the external resistors, excessively high resistor values can create significant time constants that can degrade performance. Good axial metal-film or surface-mount resistors have approximately 0.2 pF in shunt with the resistor. For resistor values > 2.0 kΩ, this parasitic capacitance can add a pole and/or a zero below 400 MHz that can effect circuit operation. Keep resistor values as low as possible, consistent with load driving considerations. A good starting point for design is to set the Rf to 249 Ω for low-gain, noninverting applications. This setting automatically keeps the resistor noise terms low and minimizes the effect of their parasitic capacitance. 4. Connections to other wideband devices on the board may be made with short direct traces or through onboard transmission lines. For short connections, consider the trace and the input to the next device as a lumped capacitive load. Relatively wide traces (50 mils to 100 mils) should be used, preferably with ground and 26 www.ti.com power planes opened up around them. Estimate the total capacitive load and set RISO from the plot of recommended RISO vs capacitive load (See Figure 88). Low parasitic capacitive loads (<4 pF) may not need an R(ISO), since the THS4211 is nominally compensated to operate with a 2-pF parasitic load. Higher parasitic capacitive loads without an R(ISO) are allowed as the signal gain increases (increasing the unloaded phase margin). If a long trace is required, and the 6-dB signal loss intrinsic to a doubly-terminated transmission line is acceptable, implement a matched impedance transmission line using microstrip or stripline techniques (consult an ECL design handbook for microstrip and stripline layout techniques). A 50-Ω environment is normally not necessary onboard, and in fact a higher impedance environment improves distortion as shown in the distortion versus load plots. With a characteristic board trace impedance defined on the basis of board material and trace dimensions, a matching series resistor into the trace from the output of the THS4211 is used as well as a terminating shunt resistor at the input of the destination device. Remember also that the terminating impedance is the parallel combination of the shunt resistor and the input impedance of the destination device: this total effective impedance should be set to match the trace impedance. If the 6-dB attenuation of a doubly terminated transmission line is unacceptable, a long trace can be series-terminated at the source end only. Treat the trace as a capacitive load in this case and set the series resistor value as shown in the plot of R(ISO) vs capacitive load (See Figure 88). This setting does not preserve signal integrity or a doubly-terminated line. If the input impedance of the destination device is low, there is some signal attenuation due to the voltage divider formed by the series output into the terminating impedance. 5. Socketing a high speed part like the THS4211 is not recommended. The additional lead length and pin-to-pin capacitance introduced by the socket can create a troublesome parasitic network which can make it almost impossible to achieve a smooth, stable frequency response. Best results are obtained by soldering the THS4211 onto the board. PowerPAD™ DESIGN CONSIDERATIONS The THS4211 and THS4215 are available in a thermally-enhanced PowerPAD family of packages. These packages are constructed using a downset leadframe upon which the die is mounted [see Figure 89(a) and Figure 89(b)]. This arrangement results in the lead frame being exposed as a thermal THS4211 THS4215 www.ti.com SLOS400D – SEPTEMBER 2002 – REVISED NOVEMBER 2004 pad on the underside of the package [see Figure 89(c)]. Because this thermal pad has direct thermal contact with the die, excellent thermal performance can be achieved by providing a good thermal path away from the thermal pad. 4. 5. The PowerPAD package allows both assembly and thermal management in one manufacturing operation. During the surface-mount solder operation (when the leads are being soldered), the thermal pad can also be soldered to a copper area underneath the package. Through the use of thermal paths within this copper area, heat can be conducted away from the package into either a ground plane or other heat dissipating device. The PowerPAD package represents a breakthrough in combining the small area and ease of assembly of surface mount with the heretofore awkward mechanical methods of heatsinking. 6. DIE Side View (a) Thermal Pad DIE End View (b) Bottom View (c) Figure 89. Views of Thermally Enhanced Package Although there are many ways to properly heatsink the PowerPAD package, the following steps illustrate the recommended approach. Single or Dual 68 Mils x 70 Mils (Via Diameter = 13 Mils) Figure 90. PowerPAD PCB Etch and Via Pattern PowerPAD PCB LAYOUT CONSIDERATIONS 1. Prepare the PCB with a top side etch pattern as shown in Figure 90. There should be etching for the leads as well as etch for the thermal pad. 2. Place five holes in the area of the thermal pad. These holes should be 13 mils in diameter. Keep them small so that solder wicking through the holes is not a problem during reflow. 3. Additional vias may be placed anywhere along the thermal plane outside of the thermal pad area. They help dissipate the heat generated by the THS4211 and THS4215 IC. These additional vias may be larger than the 13-mil diameter vias 7. 8. directly under the thermal pad. They can be larger because they are not in the thermal pad area to be soldered, so wicking is not a problem. Connect all holes to the internal ground plane. When connecting these holes to the ground plane, do not use the typical web or spoke via connection methodology. Web connections have a high thermal resistance connection that is useful for slowing the heat transfer during soldering operations. This resistance makes the soldering of vias that have plane connections easier. In this application, however, low thermal resistance is desired for the most efficient heat transfer. Therefore, the holes under the THS4211 and THS4215 PowerPAD package should make their connection to the internal ground plane, with a complete connection around the entire circumference of the plated-through hole. The top-side solder mask should leave the terminals of the package and the thermal pad area with its five holes exposed. The bottom-side solder mask should cover the five holes of the thermal pad area. This prevents solder from being pulled away from the thermal pad area during the reflow process. Apply solder paste to the exposed thermal pad area and all of the IC terminals. With these preparatory steps in place, the IC is simply placed in position and run through the solder reflow operation as any standard surface-mount component. This results in a part that is properly installed. For a given θJA , the maximum power dissipation is shown in Figure 91 and is calculated by Equation 6: Tmax T A PD JA where PD = Maximum power dissipation of THS4211 (watts) TMAX = Absolute maximum junction temperature (150°C) TA = Free-ambient temperature (°C) θJA = θJC + θCA θJC = Thermal coefficient from junction to the case θCA = Thermal coefficient from the case to ambient air (°C/W). (6) The next consideration is the package constraints. The two sources of heat within an amplifier are quiescent power and output power. The designer should never forget about the quiescent heat generated within the device, especially multi-amplifier devices. Because these devices have linear output stages (Class AB), most of the heat dissipation is at low output voltages with high output currents. The other key factor when dealing with power dissipation is how the devices are mounted on the PCB. The PowerPAD devices are extremely useful for heat dissipation. But, the device should always be 27 THS4211 THS4215 www.ti.com SLOS400D – SEPTEMBER 2002 – REVISED NOVEMBER 2004 THERMAL ANALYSIS The THS4211 device does not incorporate automatic thermal shutoff protection, so the designer must take care to ensure that the design does not violate the absolute maximum junction temperature of the device. Failure may result if the absolute maximum junction temperature of 150°C is exceeded. The thermal characteristics of the device are dictated by the package and the PC board. Maximum power dissipation for a given package can be calculated using Equation 7: Tmax–T A P Dmax JA where PDmax is the maximum power dissipation in the amplifier (W). Tmax is the absolute maximum junction temperature (°C). TA is the ambient temperature (°C). θJA = θJC + θCA θJC is the thermal coefficient from the silicon junctions to the case (°C/W). θCA is the thermal coefficient from the case to ambient air (°C/W). (7) For systems where heat dissipation is more critical, the THS4211 is offered in an 8-pin MSOP with PowerPAD. The thermal coefficient for the MSOP PowerPAD package is substantially improved over the traditional SOIC. Maximum power dissipation levels are depicted in the graph for the two packages. The data for the DGN package assumes a board layout that follows the PowerPAD layout guidelines referenced above and detailed in the PowerPAD application notes in the Additional Reference Material section at the end of the data sheet. 28 3.5 PD - Maximum Power Dissipation - W soldered to a copper plane to fully use the heat dissipation properties of the PowerPAD. The SOIC package, on the other hand, is highly dependent on how it is mounted on the PCB. As more trace and copper area is placed around the device, θJA decreases and the heat dissipation capability increases. For a single package, the sum of the RMS output currents and voltages should be used to choose the proper package. 8-Pin DGN Package 3 2.5 2 8-Pin D Package 1.5 1 0.5 0 -40 40 60 -20 0 20 TA - Ambient Temperature - °C 80 θJA = 170°C/W for 8-Pin SOIC (D) θJA = 58.4°C/W for 8-Pin MSOP (DGN) TJ= 150°C, No Airflow Figure 91. Maximum Power Dissipation vs Ambient Temperature When determining whether or not the device satisfies the maximum power dissipation requirement, it is important to consider not only quiescent power dissipation, but also dynamic power dissipation. Often maximum power dissipation is difficult to quantify because the signal pattern is inconsistent, but an estimate of the RMS power dissipation can provide visibility into a possible problem. DESIGN TOOLS Performance vs Package Options The THS4211 and THS4215 are offered in a different package options. However, performance may be limited due to package parasitics and lead inductance in some packages. In order to achieve maximum performance of the THS4211 and THS4215, Texas Instruments recommends using the leadless MSOP (DRB) or MSOP (DGN) packages, in additions to proper high-speed PCB layout. Figure 92 shows the unity gain frequency response of the THS4211 using the leadless MSOP, MSOP, and SOIC package for comparison. Using the THS4211 and THS4215 in a unity gain with the SOIC package may result in the device becoming unstable. In higher gain configurations, this effect is mitigated by the reduced bandwidth. As such, the SOIC is suitable for application with gains equal to or higher than +2 V/V or (–1 V/V). THS4211 THS4215 www.ti.com SLOS400D – SEPTEMBER 2002 – REVISED NOVEMBER 2004 12 _ 10 + Small Signal Gain - dB 499 Ω 49.9 Ω 8 Normalized Gain - dB 17 SOIC, Rf = 0 Ω Rf 6 4 SOIC, Rf = 100 Ω 2 15 _ 13 + Rf Rf = 0 Ω 499 Ω 49.9 Ω 11 Rf = 50 Ω 9 7 Rf = 100 Ω 5 Rf = 200 Ω 3 1 0 -1 -2 PIN = -7 dB VS =±5 V Leadless MSOP, & MSOP Rf = 0 Ω -4 10 M 100 M PIN = -7 dBm VS = ±5 V -3 -5 1G 10 M 100 M f - Frequency - Hz Figure 92. Effects of Unity Gain Frequency Response for Differential Packages SPICE 10 G Models, Figure 93. Frequency Response vs Feedback Resistor Using the EDGE #6439527 EVM and Texas Instruments is committed to providing its customers with the highest quality of applications support. To support this goal, evaluation boards have been developed for the THS4211 operational amplifier. Three evaluation boards are available: one THS4211 and one THS4215, both configurable for different gains, and a third for untiy gain (THS4211 only). These boards are easy to use, allowing for straightforward evaluation of the device. These evaluation boards can be ordered through the Texas Instruments web site, www.ti.com, or through your local Texas Instruments sales representative. Schematics for the evaluation boards are shown below. The THS4211/THS4215 EVM board shown in Figure 95 through Figure 99 accommodates different gain configurations. Its default component values are set to give a gain of 2. The EVM can be configured for unity gain; however, it is strongly not recommended. Evaluating the THS4211/THS4215 in unity gain using this EVM may cause the device to become unstable. The stability of the device can be controlled by adding a large resistor in the feedback path, but performance is sacrificed. Figure 93 shows the small signal frequency response of the THS4211 with different feedback resistors in the feedback path. Figure 94 is the small frequency response of the THS4211 using the unity gain EVM. 5 Small Signal Gain - dB Evaluation Fixtures, Applications Support 1G f - Frequency - Hz 4 _ 3 + 499 Ω 49.9 Ω 2 1 0 -1 -2 -3 PIN = -7 dBm VS = ±5 V -4 100 k 1M 10 M 100 M f - Frequency - Hz 1G 10 G Figure 94. Frequency Response Using the EDGE #6443547 G = +1 EVM The frequency-response peaking is due to the lead inductance in the feedback path. Each pad and trace on a PCB has an inductance associated with it, which in conjunction with the inductance associated with the package may cause frequency-response peaking, causing the device to become unstable. In order to achieve the maximum performance of the device, PCB layout is very critical. Texas Instruments has developed an EVM for the evaluation of the THS4211 configured for a gain of 1. The EVM is shown in Figure 100 through Figure 104. This EVM is designed to minimize peaking in the unity gain configuration. Minimizing the inductance in the feedback path is critical for reducing the peaking of the frequency response in unity gain. The recommended maximum inductance allowed in the feedback path is 4 nH. This inductance can be calculated using Equation 8: 29 THS4211 THS4215 www.ti.com SLOS400D – SEPTEMBER 2002 – REVISED NOVEMBER 2004 L(nH) K ln 2 0.223 W T 0.5 WT where W = Width of trace in inches. = Length of the trace in inches. T = Thickness of the trace in inches. K = 5.08 for dimensions in inches, and K = 2 for dimensions in cm. (8) Vs+ J9 Power Down R8 C8 R9 R5 Vs - Vs+ 7 8 2 _ R3 J1 Vin - U1 R6 6 J4 Vout 3 + R2 R7 4 1 Vs - J2 Vin+ J8 Power Down Ref Figure 96. THS4211/THS4215 EVM Board Layout (Top Layer) C7 R1 R4 J7 VS- J6 GND J5 VS+ TP1 FB1 FB2 VS- C5 C6 VS+ C1 + C2 + C3 C4 Figure 95. THS4211/THS4215 EVM Circuit Configuration Figure 97. THS4211/THS4215 EVM Board Layout (Second Layer, Ground) 30 THS4211 THS4215 www.ti.com SLOS400D – SEPTEMBER 2002 – REVISED NOVEMBER 2004 Vs+ 7 8 2 _ U1 R6 6 J4 Vout 3 + R7 4 1 J2 Vin+ Vs R4 J7 VS- J6 GND J5 VS+ TP1 FB1 FB2 VS- C5 C6 VS+ C1 + C2 + C3 C4 Figure 100. THS4211 Unity Gain EVM Circuit Configuration Figure 98. THS4211/THS4215 EVM Board Layout (Third Layer, Power) Figure 101. THS4211 Unity Gain EVM Board Layout (Top Layer) Figure 99. THS4211/THS4215 EVM Board Layout (Bottom Layer) 31 THS4211 THS4215 www.ti.com SLOS400D – SEPTEMBER 2002 – REVISED NOVEMBER 2004 Figure 102. THS4211 Unity Gain EVM Board Layout (Second Layer, Ground) Figure 104. THS4211 Unity Gain EVM Board Layout (Bottom Layer) Computer simulation of circuit performance using SPICE is often useful when analyzing the performance of analog circuits and systems. This is particularly true for video and RF amplifier circuits, where parasitic capacitance and inductance can have a major effect on circuit performance. A SPICE model for the THS4500 family of devices is available through the Texas Instruments web site (www.ti.com). The Product Information Center (PIC) is available for design assistance and detailed product information. These models do a good job of predicting small-signal ac and transient performance under a wide variety of operating conditions. They are not intended to model the distortion characteristics of the amplifier, nor do they attempt to distinguish between the package types in their small-signal ac performance. Detailed information about what is and is not modeled is contained in the model file itself. ADDITIONAL REFERENCE MATERIAL • • Figure 103. THS4211 Unity Gain EVM Board Layout (Third Layer, Power) 32 PowerPAD Made Easy, application brief (SLMA004) PowerPAD Thermally Enhanced Package, technical brief (SLMA002) THERMAL PAD MECHANICAL DATA www.ti.com DRB (S-PDSO-N8) THERMAL INFORMATION This package incorporates an exposed thermal pad that is designed to be attached directly to an external heatsink. The thermal pad must be soldered directly to the printed circuit board (PCB). After soldering, the PCB can be used as a heatsink. In addition, through the use of thermal vias, the thermal pad can be attached directly to a ground plane or special heatsink structure designed into the PCB. This design optimizes the heat transfer from the integrated circuit (IC). For additional information on the Quad Flatpack No-Lead (QFN) package and how to take advantage of its heat dissipating abilities, refer to Application Report, Quad Flatpack No-Lead Logic Packages, Texas Instruments Literature No. SCBA017 and Application Report, 56-Pin Quad Flatpack No-Lead Logic Package, Texas Instruments Literature No. SCEA032. Both documents are available at www.ti.com. The exposed thermal pad dimensions for this package are shown in the following illustration. 1 4 Exposed Thermal Pad 1,50 +0,10 0,15 2x0,65 4x0,23 8 5 1,75 +0,10 0,15 4x0,625 NOM Bottom View NOTE: All linear dimensions are in millimeters QFND058 Exposed Thermal Pad Dimensions Thermal Pad Mechanical Data www.ti.com DGN (S–PDSO–G8) THERMAL INFORMATION The DGN PowerPAD™ package incorporates an exposed thermal die pad that is designed to be attached directly to an external heat sink. When the thermal die pad is soldered directly to the printed circuit board (PCB), the PCB can be used as a heatsink. In addition, through the use of thermal vias, the thermal die pad can be attached directly to a ground plane or special heat sink structure designed into the PCB. This design optimizes the heat transfer from the integrated circuit (IC). For additional information on the PowerPAD package and how to take advantage of its heat dissipating abilities, refer to Technical Brief, PowerPAD Thermally Enhanced Package, Texas Instruments Literature No. SLMA002 and Application Brief, PowerPAD Made Easy, Texas Instruments Literature No. SLMA004. Both documents are available at www.ti.com. See Figure 1 for DGN package exposed thermal die pad dimensions. 8 1 5 4 Exposed Thermal Die Pad 1,78 MAX 1,73 MAX Bottom View PPTD041 NOTE: All linear dimensions are in millimeters. Figure 1. DGN Package Exposed Thermal Die Pad Dimensions PowerPAD is a trademark of Texas Instruments. 1 PACKAGE OPTION ADDENDUM www.ti.com 13-Sep-2005 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Drawing Pins Package Eco Plan (2) Qty THS4211D ACTIVE SOIC D 8 75 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4211DG4 ACTIVE SOIC D 8 75 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4211DGK ACTIVE MSOP DGK 8 100 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4211DGKR ACTIVE MSOP DGK 8 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4211DGKRG4 ACTIVE MSOP DGK 8 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4211DGN ACTIVE MSOPPower PAD DGN 8 80 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4211DGNG4 ACTIVE MSOPPower PAD DGN 8 80 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4211DGNR ACTIVE MSOPPower PAD DGN 8 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4211DGNRG4 ACTIVE MSOPPower PAD DGN 8 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4211DR ACTIVE SOIC D 8 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4211DRBR ACTIVE SON DRB 8 3000 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR THS4211DRBRG4 ACTIVE SON DRB 8 3000 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR THS4211DRBT ACTIVE SON DRB 8 250 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR THS4211DRG4 ACTIVE SOIC D 8 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4215D ACTIVE SOIC D 8 75 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4215DGK ACTIVE MSOP DGK 8 100 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4215DGKR ACTIVE MSOP DGK 8 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4215DGKRG4 ACTIVE MSOP DGK 8 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4215DGN ACTIVE MSOPPower PAD DGN 8 80 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4215DGNG4 ACTIVE MSOPPower PAD DGN 8 80 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4215DGNR ACTIVE MSOPPower PAD DGN 8 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4215DGNRG4 ACTIVE MSOPPower DGN 8 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM Addendum-Page 1 Lead/Ball Finish MSL Peak Temp (3) PACKAGE OPTION ADDENDUM www.ti.com 13-Sep-2005 Orderable Device Status (1) Package Type THS4215DR ACTIVE SOIC D 8 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4215DRBR ACTIVE SON DRB 8 3000 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR THS4215DRBRG4 ACTIVE SON DRB 8 3000 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR THS4215DRBT ACTIVE SON DRB 8 250 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR THS4215DRG4 ACTIVE SOIC D 8 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM Package Drawing Pins Package Eco Plan (2) Qty Lead/Ball Finish MSL Peak Temp (3) PAD (1) 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 - The planned eco-friendly classification: Pb-Free (RoHS) or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability information and additional product content details. TBD: The Pb-Free/Green conversion plan has not been defined. 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 (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material) (3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. 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