IH5140 thru IH5145 Semiconductor CT ODU ODUCT R P PR TE OLE TITUTE High-Level CMOS Analog Switches S B April 1999 O S SUB DG401 HI-5043 E L , 1: 03 SIB 390 POS 40, IH514 42, DG4 43, HI-0 045 0 0 5 1 5 5 I 5 Features IH 42: HI 03, HI 049, H vices Description IH51 43: DG4 45: HI-5 f single de patible • Super Fast Break-Before-Make The IH5140 Family of CMOS switches utilizes Harris’ latchcom IH51 44, IH51 Switching unt o in co to be pin 1 p 5 d free junction isolated processing to build the fastest switches H n I s a e t c u i • SPST Switches (Typ) o v de Pin dual ts. TE: - tON . . . . . . .N. O . . . . . .a.llo. w . . . .m .e .n . . . . . . . . . . . . . . 80ns lace - tOFF . . . . . . . . . . . . . r.e.p. . . . . . . . . . . . . . . . . . . . 50ns • Power Supply Currents . . . . . . . . . . . . . . . . . . . . <1µA • OFF Leakages at 25oC (Typ) . . . . . . . . . . . . . . . <100pA • Non-Latching with Supply Turn-Off • Single Monolithic CMOS Chip • Plug-In Replacements for IH5040 Family and Part of the DG180 Family to Upgrade Speed and Leakage • Toggle Rate. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . >1MHz • Switches Signals with ±15V Supplies. . . . . . . . . . . . >20VP-P • TTL, CMOS Direct Compatibility currently available. These switches can be toggled at a rate of greater than 1MHz with fast tON times (80ns typical) and faster tOFF times (50ns typical), guaranteeing break before make switching. This family of switches combines the speed of the hybrid FET DG180 family with the reliability and low power consumption of a monolithic CMOS construction. Very low quiescent power is dissipated in either the ON or the OFF state of the switch. Maximum power supply current is 10µA (at 25oC) from any supply and typical quiescent currents are in the 10nA which makes these devices ideal for portable equipment and military applications. The IH5140 Family is completely compatible with TTL (5V) logic, TTL open collector logic and CMOS logic. It is pin compatible with Harris’ IH5040 family and part of the DG180/DG190 family as shown in the switching state diagrams. • Internal Diode in Series with V+ for Fault Protection Part Number Information FUNCTION TEMP. RANGE (oC) IH5140MJE SPST -55 to 125 16 Ld CerDIP IH5140CJE SPST 0 to 70 16 Ld CERDIP 16 Ld PDIP PART NUMBER PACKAGE IH5140CPE SPST 0 to 70 IH5141MJE Dual SPST -55 to 125 16 Ld CerDIP IH5141CJE Dual SPST 0 to 70 16 Ld CERDIP IH5141CPE Dual SPST 0 to 70 IH5142MJE SPDT -55 to 125 16 Ld CerDIP IH5142CJE SPDT 0 to 70 16 Ld CERDIP IH5142CPE SPDT 0 to 70 16 Ld PDIP IH5143MJE Dual SPDT -55 to 125 16 Ld CERDIP IH5143CJE Dual SPDT 0 to 70 16 Ld CerDIP IH5143CPE Dual SPDT 0 to 70 IH5144MJE DPST -55 to 125 16 Ld CERDIP IH5144CJE DPST 0 to 70 16 Ld CERDIP IH5144CPE DPST 0 to 70 16 Ld PDIP IH5145MJE Dual DPST -55 to 125 16 Ld CerDIP IH5145CJE Dual DPST 0 to 70 16 Ld CerDIP IH5145CPE Dual DPST 0 to 70 16 Ld PDIP IH5140MJE/883B SPST -55 to 125 IH5141MJE/883B Dual SPST -55 to 125 16 Ld CERDIP IH5142MJE/883B SPDT -55 to 125 16 Ld CERDIP IH5143MJE/883B Dual SPDT -55 to 125 16 Ld CERDIP IH5144MJE/883B DPST -55 to 125 16 Ld CERDIP IH5145MJE/883B Dual DPST -55 to 125 16 Ld CERDIP PKG. NO. 16 Ld PDIP 16 Ld PDIP 16 Ld CERDIP NOTE: 1. For MIL-STD-883 compliant parts, request the /883 datasheet on the above products. CAUTION: These devices are sensitive to electrostatic discharge. Users should follow proper IC Handling Procedures. Copyright © Harris Corporation 1999 13-1 File Number 3132.2 IH5140 thru IH5145 Pinouts IH5140 (PDIP, CERDIP) TOP VIEW IH5141 (PDIP, CERDIP) TOP VIEW 16 S D1 1 16 S1 NC 2 15 IN NC 2 15 IN1 NC 3 14 V- NC 3 14 V- NC 4 13 GND NC 4 13 GND NC 5 12 VL NC 5 12 VL NC 6 11 V+ NC 6 11 V+ NC 7 10 NC NC 7 10 IN2 NC 8 9 NC D2 8 9 S2 D 1 IH5142 (PDIP, CERDIP) TOP VIEW D1 1 IH5143 (PDIP, CERDIP) TOP VIEW 16 S1 D1 1 16 S1 2 15 IN NC 15 IN1 D2 3 14 V- D3 3 14 V- S2 4 13 GND S3 4 13 GND NC 12 VL S4 5 12 VL 11 V+ 10 IN2 NC 5 2 NC 6 11 V+ D4 6 NC 7 10 NC NC NC D2 8 9 NC 8 7 IH5144 (PDIP, CERDIP) TOP VIEW 9 S2 IH5145 (PDIP, CERDIP) TOP VIEW 16 S1 D1 1 16 S1 NC 2 15 IN NC 2 15 IN1 D2 3 14 V- D3 3 14 V- S2 4 13 GND S3 4 13 GND NC 5 12 VL S4 5 12 VL NC 6 11 V+ D4 6 11 V+ NC 7 10 NC NC 7 10 IN2 9 NC D2 8 9 S2 D1 1 NC 8 13-2 IH5140 thru IH5145 Functional Block Diagram TYPICAL DRIVER/GATE - IH5142 V+ Q3 Q7 S1 Q5 Q18 10kΩ 5kΩ Q2 T2L INPUT 100Ω Q16 Q1 D1 Q8 Q17 Q12 V5kΩ S2 3kΩ Q13 Q9 Q4 Q6 Q15 Q11 Q10 D2 V+ Q14 VL V- 13-3 IH5140 thru IH5145 Switching State Diagrams DIP (JE, PE) SPST IH5140 VL DIP (JE, PE) DUAL SPST IH5141 V+ 12 VL 11 V+ 12 11 1 16 S1 1 16 D S D1 15 IN1 15 IN IN2 10 8 9 D2 S2 13 GND 14 13 GND V- DIP (JE, PE) SPDT IH5142 VL 12 VL 1 3 S2 IN S1 D1 4 S3 D2 IN2 GND 11 16 1 4 3 D3 15 14 S2 S4 V- 10 9 8 5 6 GND DIP (JE, PE) DPST IH5144 12 S1 D1 3 S2 S3 D2 IN2 GND V+ 11 16 1 4 3 D1 D3 15 IN1 15 13 V- 12 1 4 IN VL 11 S1 14 DIP (JE, PE) DUAL DPST IH5145 V+ 16 D2 D4 13 VL D1 IN1 15 13 V+ 12 11 S1 V- DIP (JE, PE) DUAL SPDT IH5143 V+ 16 14 14 S2 S4 V- 10 9 8 5 6 D4 13 GND 13-4 D2 14 V- IH5140 thru IH5145 Absolute Maximum Ratings Thermal Information V+ to V-. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <36V V+ to VD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <30V VD to V- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <30V VD to VS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <±22V VL to V- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <33V VL to VIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <30V VL to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <20V VIN to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <20V Current (Any Terminal) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30mA Thermal Resistance (Typical) θJA (oC/W) θJC (oC/W) CERDIP Package . . . . . . . . . . . . . . . . 80 24 PDIP Package . . . . . . . . . . . . . . . . . . . 100 N/A Maximum Junction Temperature CERDIP Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175oC PDIP Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150oC Maximum Storage Temperature Range . . . . . . . . . -65oC to 150oC Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . . 300oC Operating Conditions Temperature Ranges Military . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -55oC to 125oC Commercial. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0oC to 70oC CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. Electrical Specifications 25oC, V+ = +15V, V- = -15V, VL = +5V MILITARY PER CHANNEL PARAMETER TEST CONDITIONS COMMERCIAL -55oC 25oC 125oC 0o C 25oC 70oC UNITS LOGIC INPUT Input Logic Current, IINH VIN = 2.4V, Note 1 ±1 ±1 10 − ±10 10 µA Input Logic Current, IINL VIN = 0.8V, Note 1 ±1 ±1 10 − ±10 10 µA IS = -10mA, VANALOG = -10V to +10V 50 50 75 75 75 100 Ω Channel to Channel rDS(ON) Match, ∆rDS(ON) - 25 (Typ) - - 30 (Typ) - Ω Minimum Analog Signal Handling Capability, VANALOG - ±11 (Typ) - - ±10 (Typ) - V SWITCH Drain Source On Resistance, rDS(ON) Switch OFF Leakage Current, ID(OFF)+IS(OFF) VD = +10V, VS = -10V - ±0.5 100 - ±5 100 nA VD = -10V, VS = +10V - ±0.5 100 - ±5 100 nA Switch On Leakage Current, ID(ON)+IS(ON) VD = VS = -10V to +10V - ±1 200 - ±2 200 nA Minimum Channel to Channel Cross Coupling Rejection Ratio, CCRR One Channel Off; Any Other Channel Switches, See Performance Characteristics - 54 (Typ) - - 50 (Typ) - dB Switch “ON” Time, tON See Switching Time Specifications and Timing Diagrams Switch “OFF” Time, tOFF See Switching Time Specifications and Timing Diagrams Charge Injection, Q(INJ) See Performance Characteristics - 10 (Typ) - - 15 (Typ) - pC Minimum Off Isolation Rejection Ratio, OIRR f = 1MHz, RL = 100Ω, CL ≤ 5pF, See Performance Characteristics - 54 (Typ) - - 50 (Typ) - dB 1.0 1.0 10 10 10 100 µA 1.0 1.0 10 10 10 100 µA 1.0 1.0 10 10 10 100 µA 1.0 1.0 10 10 10 100 µA SUPPLY + Power Supply Quiescent Current, I+ V+ = +15V, V- = -15V, - Power Supply Quiescent Current, I- VL = +5V, See Performance Characteristics +5V Supply Quiescent Current, IL Ground Supply Quiescent Current, IGND NOTES: 1. Some channels are turned on by high (1) logic inputs and other channels are turned on by low (0) inputs; however 0.8V to 2.4V describes the minimum range for switching properly. Refer to logic diagrams to find logical value of logic input required to produce ON or OFF state. 2. Typical values are for design aid only, not guaranteed and not subject to production testing. 13-5 IH5140 thru IH5145 Switching Time Specifications PART NUMBER IH5140, IH5141 tON , tOFF are Maximum Specifications and tON - tOFF is Minimum Specification TEST CONDITIONS 125oC 0 oC 25oC 70oC UNITS - 100 - - 150 - ns Switch “OFF” Time, tOFF - 75 - - 125 - ns Break-Before-Make, tON - tOFF - 10 - - 5 - ns - 150 - - 175 - ns - 125 - - 150 - ns - 175 - - 250 - ns Switch “OFF” Time, tOFF - 125 - - 150 - ns Break-Before-Make, tON - tOFF - 10 - - 5 - ns - 200 - - 300 - ns - 125 - - 150 - ns - 175 - - 250 - ns Switch “OFF” Time, tOFF - 125 - - 150 - ns Break-Before-Make, tON - tOFF - 10 - - 5 - ns - 200 - - 300 - ns Switch “OFF” Time, tOFF - 125 - - 150 - ns Break-Before-Make, tON - tOFF - 10 - - 5 - ns - 175 - - 250 - ns Switch “OFF” Time, tOFF - 125 - - 150 - ns Break-Before-Make, tON - tOFF - 10 - - 5 - ns - 200 - - 300 - ns - 125 - - 150 - ns SPECIFICATIONS Switch “ON” Time, tON Figure 8, Note 2 Figure 7 Switch “OFF” Time, tOFF Switch “ON” Time, tON Switch “ON” Time, tON Figure 8, Note 2 Figure 7 Switch “OFF” Time, tOFF Switch “ON” Time, tON Switch “ON” Time, tON IH5144, IH5145 COMMERCIAL 25oC Switch “ON” Time, tON IH5142, IH5143 MILITARY -55oC Switch “ON” Time, tON Switch “ON” Time, tON Figure 2, Note 2 Figure 3, Note 2 Figure 8, Note 2 Figure 7 Switch “OFF” Time, tOFF NOTES: 1. Switching times are measured at 90% points. 2. Typical values are for design aid only, not guaranteed and not subject to production testing. 13-6 IH5140 thru IH5145 Typical Performance Curves 90 100 TA = 25oC IH5141 DATA 80 90 70 80 rDS(ON) (Ω) rDS(ON) (Ω) IH5141 DATA 60 50 ±5V, +5V SUPPLIES 60 ±10V, +5V SUPPLIES 50 125oC 40 40 25oC ±15V, +5V SUPPLIES 30 -55oC 30 20 +10 +8 +6 +4 +2 0 -2 -4 -6 -8 20 +10 -10 +8 FIGURE 1. rDS(ON) vs TEMPERATURE AT ±15V, +5V SUPPLIES VOUT/VANALOG (dB) +6 +4 +2 0 -2 COAX TO SCOPE VOUT 1 16 -100 51Ω 2 15 -80 -60 -20 VANALOG - 10VP-P 100K 1M 51Ω 3 14 -15V 4 13 5 12 +5V 6 11 7 10 8 9 +15V C = 1µF SOCKET ON COPPER GROUND PLANE JIG 0 10K -8 AT FREQUENCY -40 1K -6 FIGURE 2. rDS(ON) vs POWER SUPPLIES -120 100 -4 ANALOG SIGNAL VOLTAGE (V) ANALOG SIGNAL VOLTAGE (V) 10M FREQUENCY (Hz) FIGURE 3A. FIGURE 3B. FIGURE 3. “OFF” ISOLATION vs FREQUENCY 2.8 I (mA) 2.6 2.4 2.2 1 16 2.0 2 15 1.8 3 14 -15V 4 13 5 12 +5V 6 11 +15V 7 10 I+ SUPPLY 1.6 1.4 1.2 1.0 I- SUPPLY 0.8 0.6 0.4 8 IGND 0.2 0 1 9 +10V IL < 0.05mA FROM 1µs to DC 10 100 τ - PERIOD OF PULSE REPETITION RATE (µs) τ +3V ρ 100Ω 1000 FIGURE 4A. FIGURE 4B. FIGURE 4. POWER SUPPLY CURRENTS vs LOGIC STROBE RATE 13-7 0V ρ = 400ns -10 IH5140 thru IH5145 Typical Performance Curves (Continued) NC CHANNEL PINS (3, 4) VINJECT +100 +10 0.01µF 16 V A 2 15 VA 3 CHARGE (pC) VINJECT (mVP-P) +5 1 0 -5 -10 0.01µF -100 NC CHANNEL PINS (1, 16) +3V 0V 14 -15V 4µs 13 4 IH5143 5 12 +5V 6 11 +15V 7 10 8 9 +VINJECT +VINJECT 0mV -VINJECT 0mV -10 -5 0 +5 +10 -VINJECT ANALOG SIGNAL VOLTAGE (V) FIGURE 5A. FIGURE 5B. FIGURE 5. CHARGE INJECTION vs ANALOG SIGNAL COAX TO SCOPE VOUT/VANALOG (dB) -120 VOUT (OFF CHANNEL) -100 16 1 51Ω 2 15 C 3 -80 13 4 C 5 -60 C 6 -40 (ON CHANNEL) 0 100 C 7 1K 10K 100M 1M 12 +5V 11 +15V 10 +5V 9 8 -20 1kΩ C = 1µF COPPER GROUND PLANE JIG 10M FREQUENCY (Hz) FIGURE 6A. FIGURE 6B. FIGURE 6. CHANNEL TO CHANNEL CROSS COUPLING REJECTION vs FREQUENCY Test Circuits and Waveforms VOUT A 10pF 1kΩ 1 16 ±10V 2 15 3 14 -15V IH5141 6 12 +5V +15V 11 7 10 8 9 5 VOUT B 10pF +3V 13 4 0V TTL INPUT ±10V 1kΩ FIGURE 7. IH5141 tON AND tOFF (3V DIGITAL INPUT) 13-8 51Ω 14 -15V 10VP-P AT FREQUENCY = VANALOG IH5140 thru IH5145 Test Circuits and Waveforms (Continued) tON VOUT A 1 16 2 15 3 14 4 13 +15V TTL INPUT +10V 10pF 1kΩ 0V 12 11 6 +15V 0V -10V 0V 9 -10V 8 10pF TTL INPUT LOGIC INPUT 10 7 VOUT +10V +15V 1N914 +15V VOUT B 0V 0V -15V IH5141 5 tOFF 1kΩ tON VOUT tOFF NOTE: Switching times are measured at 90% points. FIGURE 8. IH5141 tON AND tOFF (15V DIGITAL INPUT) 10pF 1kΩ 1 16 +10V 2 15 3 14 -15V -10V 4 -10V 5 tON 13 +15V IH5143 VOUT B 12 1kΩ +15V -10V TTL INPUT 10% 0V 9 +10V 8 FIGURE 9A. FIGURE 9B. FIGURE 9. IH5143 tON AND tOFF (15V DIGITAL INPUT) VOUT A 10pF 1kΩ +10V VOUT B 1 16 +10V 2 15 3 14 -15V IH5143 5 12 +5V 6 11 +15V 7 10 0V TTL INPUT 9 +10V 8 10pF +3V 13 4 1kΩ FIGURE 10. IH5143 tON AND tOFF (3V DIGITAL INPUT) 13-9 VOUT A OR B +15V 10 7 10pF 90% 0V 11 6 tOFF +10V T2L INPUT IH5140 thru IH5145 Typical Applications ANALOG IN To maximize switching speed on the IH5140 family, TTL open collector logic (15V with a 1kΩ or less collector resistor) should be used. This configuration will result in (SPST) tON and tOFF times of 80ns and 50ns, for signals between -10V and +10V. The SPDT and DPST switches are approximately 30ns slower in both tON and tOFF with the same drive configuration. 15V CMOS logic levels can be used (0V to +15V), but propagation delays in the CMOS logic will slow down the switching (typical 50ns → 100ns delays). When driving the IH5140 Family from either +5V TTL or CMOS logic, switching times run 20ns slower than if they were driven from +15V logic levels. Thus tON is about 105ns, and tOFF 75ns for SPST switches, and 135ns and 105ns (tON, tOFF) for SPDT or DPST switches. The low level drive can be made as fast as the high level drive if ±5V strobe levels are used instead of the usual 0V → +3.0V drive. Pin 13 is taken to -5V instead of the usual GND and strobe input is taken from +5V to -5V levels as shown in Figure 11. ANALOG OUT 2 16 ANALOG IN (CHANNEL A) 15 3 14 -15V 4 13 -5V 1 IH5141 ANALOG OUT 5 12 +5V 6 11 +15V 7 10 8 9 ±15V FROM DRIVERS Q1 D D G S SUBSTRATE Q2 D G B B S S G Q3 -15V “BODY PULLER” FET ANALOG OUT FIGURE 12. Current will flow from -10V analog voltage through the drain to body junction of Q1, then through the drain to body junction of Q3 to GND. This means that there is 10V across two forward-biased silicon diodes and current will go to whatever value the input signal source is capable of supplying. If the analog input signal is derived from the same supplies as the switch this fault condition cannot occur. Turning off the supplies would turn off the analog signal at the same time. ANALOG IN = -10V Q1 N Q2 P SUBSTRATE +5V N -5V ±15V FROM DRIVERS CMOS LEVEL INPUT STROBE P GND WHEN POWER SUPPLIES ARE OFF N N Q3 ANALOG IN (CHANNEL B) GND WHEN POWER SUPPLIES ARE OFF FIGURE 11. FIGURE 13. The typical channel of the IH5140 family consists of both P-Channel and N-channel MOSFETs. The N-channel MOSFET uses a “Body Puller” FET to drive the body to -15V (±15V supplies) to get good breakdown voltages when the switch is in the off state (see Figure 12). This “Body Puller” FET also allows the N-Channel body to electrically float when the switch is in the on state producing a fairly constant rDS(ON) with different signal voltages. While this “Body Puller” FET improves switch performance, it can cause a problem when analog input signals are present (negative signals only) and power supplies are off. This fault condition is shown in Figure 13. This fault situation can also be eliminated by placing a diode in series with the negative supply line (pin 14) as shown in Figure 14. Now when the power supplies are off and a negative input signal is present this diode is reverse biased and no current can flow. OUTA 1 16 INA 2 15 T2LAIN 3 14 4 13 IH5141 5 12 +5V 6 11 +15V 7 10 T2LBIN OUTB 8 9 INB FIGURE 14. 13-10 1N914 OR EQUIVALENT -15V IH5140 thru IH5145 Typical Switching Waveforms Scale: Vertical = 5V/Div., Horizontal = 100ns/Div. FIGURE 15B. 25oC FIGURE 15A. -55oC FIGURE 15C. 125oC NOTE: Corresponds to Figure 12 FIGURE 15. TTL OPEN COLLECTOR LOGIC DRIVE FIGURE 16B. 25oC FIGURE 16A. -55oC 13-11 IH5140 thru IH5145 Typical Switching Waveforms Scale: Vertical = 5V/Div., Horizontal = 100ns/Div. (Continued) FIGURE 16C. 125oC NOTE: Corresponds to Figure 13 FIGURE 16. TTL OPEN COLLECTOR LOGIC DRIVE NOTE: Corresponds to Figure 14 NOTE: Corresponds to Figure 19 FIGURE 17. 25oC TTL OPEN COLLECTOR LOGIC DRIVE FIGURE 18. 25oC TTL OPEN COLLECTOR LOGIC DRIVE Typical Applications +15V 7 +15V 2 2 ANALOG INPUT 3 7 741HS 4 -15V 6 1 16 2 15 3 14 4 13 5 12 6 11 7 10 8 9 3 8007 4 -15V 51Ω -15V 10,000pF POLYSTYRENE +5V +15V LOGIC INPUT +3V = > SAMPLE MODE 0V = > HOLD MODE IH5143 FIGURE 19. FIGURE 19. IMPROVED SAMPLE AND HOLD USING IH5143 13-12 6 OUTPUT IH5140 thru IH5145 Typical Applications (Continued) -VANALOG EXAMPLE: If -VANALOG = -10VDC and +VANALOG = +10VDC then Ladder Legs are switched between ±10VDC , depending upon state of Logic Strobe. 2R R 1 16 2 15 3 14 4 13 5 12 6 11 7 10 8 9 2R R +VANALOG -15V T2L LOGIC STROBE +5V +15V T2L LOGIC STROBE +VANALOG IH5143 R 0V = > HOLD MODE ETC. ETC. FIGURE 20. USING THE CMOS SWITCH TO DRIVE AN R/2R LADDER NETWORK (2 LEGS) 100kΩ 100kΩ SIGNAL INPUT 100kΩ C HI PASS OUTPUT - 8021 + 3M 100kΩ Constant gain, constant Q, variable frequency filter which provides simultaneous Lowpass, Bandpass, and Highpass outputs. With the component values shown, center frequency will be 235Hz and 23.5Hz for high and low logic inputs respectively, Q = 100, and Gain = 100. 10,000pF BANDPASS OUTPUT - 8021 + 3M 1kΩ 10,000pF 8021 + 3M LO PASS OUTPUT 100kΩ 680kΩ R 68kΩ R 68kΩ R 680kΩ R IH5143 1 f N = Center Frequency = ----------------2π RC 3V 0V LOGIC STROBE FIGURE 21. DIGITALLY TUNED LOW POWER ACTIVE FILTER 13-13 C -