IMP38C/HC/42/3/4/5 POWER MANAGEMENT BiCMOS Current-Mode PWM Controllers Key Features - 1MHz Operation - No Cross-Conduction Current - 50ns Current-Sense Delay The IMP38C4x and IMP38HC4x are fixed frequency, high performance, current-mode PWM controllers that are pin compatible with bipolar 384x devices but feature improvements resulting from IMP's BiCMOS processing and circuit design. Notable among the improvements are zero cross-conduction/shoot-through current, reduced start-up and operating current, lower current-sense delay, higher frequency operation, full supply voltage swing at the output and a 1% trimmed voltage reference. IMP38C4x and IMP38HC4x output driver stage has zero cross-conduction current. A proprietary output state-machine monitors each output MOSFET and guarantees by design zero cross-conduction current. This is an industry first for 384x PWM devices. 384x Series Pinout with BiCMOS Technology Zero Cross-Conduction Current by Design 1MHz Operation 65ns Maximum Current-Sense Delay 120A Maximum Start-Up Current 1.5mA Maximum Operating Current High Output Current Drive - 1.0A, IMP38HC4x - 0.5A, IMP38C4x 20V Maximum Supply Voltage 2.5V, 1%, Trimmed Error Amplifier Reference Trimmed Oscillator Discharge Current Pin-for-Pin Enhanced Replacements for Micrel MIC38C/HC4x and GMT38C4x/HC4x Under-voltage lockout (UVL) performance has been improved. When the power supply voltage is below the startup voltage, internal circuitry puts the output into a low impedance state. The output will sink 20mA and remain below 1.3V, well below the turn-on threshold voltage of the external MOSFET. Even when VDD drops to zero volts, the out pin will not rise above approximately 1.3V because the output UVLO circuit is Block Diagrams VDD 7 (12) (11) VD + VREF 5V Reference 8 (14) UVLO - + - RTCT COMP FB 4 (7) 6 (10) Oscillator OUT 1 (1) 2 (3) - 2R - EA 1V + + - R COMP T Q S Q R + 2.5V Ref ( (8) ) Pins Are 14-Pin Devices Only 3 (5) PGND Connection Notes IMP38C4X, IMP38HC4X (8-Pin Devices) GND 5 AGND (9) ISNS 50% Maximum Duty Cycle: IMP38C44, IMP38HC44, IMP38C45, IMP38HC45 96% Maximum Duty Cycle: IMP38C42, IMP38HC42, IMP38C43, IMP38HC43 (c) 2000 IMP, Inc. 408-432-9100/www.impweb.com 38C/HC_01.eps 1 IMP38C/HC/42/3/4/5 powered through the out pin. Leakage current from the external power MOSFETs will not force the PWM output to rise and turn the external MOSFETs on. For maximum application flexibility, start-up voltage ranges from 14.5V to 8.4V. Start-up current has been reduced to 120A maximum and operating current has been reduced to 1.5mA maximum. Current-sense propagation delay time is 35ns typical, 65ns maximum, representing an up to 75 percent reduction over other 38xx implementations. The IMP38C4x/IMP38HC4x are available in 8-pin and 14-pin DIP and SO packages as well as the 8-pin MicroSO package. The 14pin devices provide separate pins for the controller power supply and the output driver supply. This configuration maximizes application flexibility and performance. The 14-pin package can also dissipate more power. Devices in the compact 8-pin packages do not have separate output drive supply connections. Output stage drive is 0.5A for IMP38C4x devices. The high-drive IMP38HC4x family is rated at 1.0A peak current drive. Like conventional 384x controllers, the IMP38C4x and IMP38HC4x controllers use the current-mode architecture for superior load regulation, pulse-by-pulse current limiting and output MOSFET protection. All versions operate up to 20 volts. The IMP38C4x and IMP38HC4x families operate over the -40C to +85C temperature range. Pin Configuration SO/MicroSO/DIP COMP 1 FB 2 IMP38C4x IMP38HC4x SO/DIP COMP 1 8 VREF 7 VDD FB 3 ISNS 3 6 OUT RT/CT 4 5 GND 14 VREF NC 2 13 NC NC 4 IMP38C4x 12 VDD IMP38HC4x 11 V D ISNS 5 10 OUT 38C/HC_02.eps NC 6 9 AGND RT/CT 7 8 PGND 38C/HC_03.eps Pin Descriptions Pin Number Name Function 8-Pin Package 14-Pin Package 1 1 COMP 2 3 FB 3 5 ISNS 4 7 RT/CT 5 8 GND/PGND 6 10 OUT High-power, totem-pole driver output. OUT pin is actively held LOW when VCC is below the UVLO threshold. 7 12 VDD Supply voltage input. 8 14 VREF 5V-reference voltage output. 9 AGND 11 VD Output driver supply voltage for 14-pin package. 2, 4, 6, 13 NC No internal connection. Output of the Error amplifier and input to the PWM comparator. Inverting input of the Error Amplifier. Current sense comparator input. It is internally limited to 1V. Oscillator RC timing component connection. Resistor RT is connected to VREF and capacitor CT is connected to ground. Different values of RT and CT determine the maximum duty cycle. Combined power and analog ground for 8-pin packaged devices and power ground for 14-pin package. Analog ground connection for 14-pin package. 38C-HC_t01.eps 2 408-432-9100/www.impweb.com (c) 2000 IMP, Inc. !S IMP38C/HC/42/3/4/5 Ordering Information IMP Ordering Part Number Package IMP38C42EPA IMP38C42EPD IMP38C42ESA IMP38C42ESD IMP38C42EMA IMP38C42/D IMP38C43EPA IMP38C43EPD IMP38C43ESA IMP38C43ESD IMP38C43EMA IMP38C43/D IMP38C44EPA IMP38C44EPD IMP38C44ESA IMP38C44ESD IMP38C44EMA IMP38C44/D IMP38C45EPA IMP38C45EPD IMP38C45ESA IMP38C45ESD IMP38C45EMA IMP38C45/D IMP38HC42EPA IMP38HC42EPD IMP38HC42ESA IMP38HC42ESD IMP38HC42EMA IMP38HC42/D IMP38HC43EPA IMP38HC43EPD IMP38HC43ESA IMP38HC43ESD IMP38HC43EMA IMP38HC43/D IMP38HC44EPA IMP38HC44EPD IMP38HC44ESA IMP38HC44ESD IMP38HC44EMA IMP38HC44/D IMP38HC45EPA IMP38HC45EPD IMP38HC45ESA IMP38HC45ESD IMP38HC45EMA IMP38HC45/D 8-Plastic DIP 14-Plastic DIP 8-SO 14-SO 8-MicroSO DIE 8-Plastic DIP 14-Plastic DIP 8-SO 14-SO 8-MicroSO DIE 8-Plastic DIP 14-Plastic DIP 8-SO 14-SO 8-MicroSO DIE 8-Plastic DIP 14-Plastic DIP 8-SO 14-SO 8-MicroSO DIE 8-Plastic DIP 14-Plastic DIP 8-SO 14-SO 8-MicroSO DIE 8-Plastic DIP 14-Plastic DIP 8-SO 14-SO 8-MicroSO DIE 8-Plastic DIP 14-Plastic DIP 8-SO 14-SO 8-MicroSO DIE 8-Plastic DIP 14-Plastic DIP 8-SO 14-SO 8-MicroSO DIE Operating Temperature Range Startup Voltage Minimum Operating Voltage Maximum Duty Cycle Reference Voltage Peak Output Current Drive - 40C to 85C - 40C to 85C - 40C to 85C - 40C to 85C - 40C to 85C 14.5V 14.5V 14.5V 14.5V 14.5V 9.0V 9.0V 9.0V 9.0V 9.0V 96% 96% 96% 96% 96% 2.5V 2.5V 2.5V 2.5V 2.5V 0.5A 0.5A 0.5A 0.5A 0.5A - 40C to 85C - 40C to 85C - 40C to 85C - 40C to 85C - 40C to 85C 8.4V 8.4V 8.4V 8.4V 8.4V 7.6V 7.6V 7.6V 7.6V 7.6V 96% 96% 96% 96% 96% 2.5V 2.5V 2.5V 2.5V 2.5V 0.5A 0.5A 0.5A 0.5A 0.5A - 40C to 85C - 40C to 85C - 40C to 85C - 40C to 85C - 40C to 85C 14.5V 14.5V 14.5V 14.5V 14.5V 9.0V 9.0V 9.0V 9.0V 9.0V 50% 50% 50% 50% 50% 2.5V 2.5V 2.5V 2.5V 2.5V 0.5A 0.5A 0.5A 0.5A 0.5A - 40C to 85C - 40C to 85C - 40C to 85C - 40C to 85C - 40C to 85C 8.4V 8.4V 8.4V 8.4V 8.4V 7.6V 7.6V 7.6V 7.6V 7.6V 50% 50% 50% 50% 50% 2.5V 2.5V 2.5V 2.5V 2.5V 0.5A 0.5A 0.5A 0.5A 0.5A - 40C to 85C - 40C to 85C - 40C to 85C - 40C to 85C - 40C to 85C 14.5V 14.5V 14.5V 14.5V 14.5V 9.0V 9.0V 9.0V 9.0V 9.0V 96% 96% 96% 96% 96% 2.5V 2.5V 2.5V 2.5V 2.5V 1.0A 1.0A 1.0A 1.0A 1.0A - 40C to 85C - 40C to 85C - 40C to 85C - 40C to 85C - 40C to 85C 8.4V 8.4V 8.4V 8.4V 8.4V 7.6V 7.6V 7.6V 7.6V 7.6V 96% 96% 96% 96% 96% 2.5V 2.5V 2.5V 2.5V 2.5V 1.0A 1.0A 1.0A 1.0A 1.0A - 40C to 85C - 40C to 85C - 40C to 85C - 40C to 85C - 40C to 85C 14.5V 14.5V 14.5V 14.5V 14.5V 9.0V 9.0V 9.0V 9.0V 9.0V 50% 50% 50% 50% 50% 2.5V 2.5V 2.5V 2.5V 2.5V 1.0A 1.0A 1.0A 1.0A 1.0A - 40C to 85C - 40C to 85C - 40C to 85C - 40C to 85C - 40C to 85C 8.4V 8.4V 8.4V 8.4V 8.4V 7.6V 7.6V 7.6V 7.6V 7.6V 50% 50% 50% 50% 50% 2.5V 2.5V 2.5V 2.5V 2.5V 1.0A 1.0A 1.0A 1.0A 1.0A 38C/HC_t02.eps For SO and MicroSO packages, append "/T" to the ordering part number for tape and reel packaging. (c) 2000 IMP, Inc. PWM Controllers 3 IMP38C/HC/42/3/4/5 Absolute Maximum Ratings VCC Supply Voltage . . . . . . . . . . . . . . . . . . . . . . 20V VCC Supply Current . . . . . . . . . . . . . . . . . . . . . . 30mA IOUT Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.0A Current-Sense and Feedback Inputs . . . . . . . . 0.3V to 5.5V Operation Junction Temperature . . . . . . . . . . . +150C Storage Temperature . . . . . . . . . . . . . . . . . . . . . - 65C to +150C Lead Soldering Temperature (10 seconds) . . . +300C Package Thermal Resistance 8-Pin Plastic DIP (JA) . . . . . . . . . . . . . . . . . 125C/W 8-Pin MicroSO (JA) . . . . . . . . . . . . . . . . . . . 250C/W 8-Pin SO (JA) . . . . . . . . . . . . . . . . . . . . . . . . 170C/W 14-Pin Plastic DIP (JA) . . . . . . . . . . . . . . . . 90C/W 14-Pin SO (JA) . . . . . . . . . . . . . . . . . . . . . . . 145C/W Note: All voltages are referenced to GND. These are stress ratings only and functional operation is not implied. Exposure to absolute maximum ratings for prolonged time periods may affect device reliability. Electrical Characteristics Unless otherwise noted, VCC = 15V, RT = 10k and CT = 3.3nF. Specifications are over the - 40C to +85C ambient temperature range. Bold/blue specifications indicate enhanced performance features. Parameter Symbol Conditions Min Typ Max Units TA = +25C, IO = 1mA 4.90 5.00 5.10 V 2 20 mV 1 25 Reference Output voltage VREF 12V VCC 18V, IOUT = 5A Line Regulation 1mA IO 20mA Load Regulation Temperature Stability TCREF Total Reference Variation Output Noise Voltage Line, Load, Temperature, Note 1 VN Long Term Stability Output Short Circuit Note 1 mV 0.2 4.82 10Hz f 10kHz, TA = +25C, Note 1 mV/C 5.18 TA = 125C, 1000 Hours, Note 1 V V 50 TBD mV - 30 - 40 - 180 mA 49 52 55 kHz 12V VCC 18V 0.2 1.0 Note 1 0.04 ISC Oscillator Section Initial Accuracy fINIT Voltage Stability Temperature Stability TCOSC Discharge Current Amplitude peak-to-peak VOSC, P-P TA = 25C, Note 5 % %/C VRT/CT = 2V 7.2 8.4 12.0 mA VRT/CT peak-to-peak 1.1 1.7 2.3 V 2.45 2.50 2.55 V 1 A Error Amplifier Section Input Voltage VIN VCOMP = 2.5V Input Bias Current IB VFB = 4.5V 2V VO 4V, Note 1 65 90 dB Unity Gain Bandwidth UGBW Note1 0.7 1.0 MHz Power Supply Rejection Ratio PSRR mA Open Loop Gain AVOL VSTART VCC VCCMAX 60 IOL VFB = 2.7V, Vcomp = 1.1V 2 6 Output Source Current IOH VFB = 2.3V, Vcomp = 5.0V - 0.5 - 1.0 VOUT High VOH VFB = 2.3V, RL = 15k to ground 4.5 4.6 5.0 V VOUT Low VOL VFB = 2.7V, RL = 15k to VREF 0.30 0.50 V Output Sink Current 4 -1 408-432-9100/www.impweb.com dB mA (c) 2000 IMP, Inc. !S IMP38C/HC/42/3/4/5 Electrical Characteristics Unless otherwise noted, VCC = 15V, RT = 10k and CT = 3.3nF. Specifications are over the - 40C to +85C ambient temperature range. Bold/blue specifications indicate enhanced performance features. Parameter Symbol Current Sense Gain Over Current Protection Threshold Power Supply Rejection Ratio Input Bias Current Delay to Output Output IMP38C4x ON Resistance, High ON Resistance, Low IMP38HC4x ON Resistance, High ON Resistance, Low Peak Drive Current IMP38C4x Rise Time IMP38C4x Fall Time IMP38HC4x Rise Time IMP38HC4x Fall Time Shoot-through Current Undervoltage Lockout Start Threshold AVOL PSRR IB TPD Min Typ Max Units Notes 1, 2 and 3 Vcomp = max, Note 2 VSTART VCC 18V 2.90 0.9 3.00 0.98 70 - 0.1 50 3.10 1.1 V/V V dB A ns VFB = 0V, ISNS 0V to 2V, CL = 1nF ISOURCE = 0.2A ISINK = 0.2A 20 11 RDS (ON) ISOURCE = 0.2A ISINK = 0.2A HC devices H devices TA = 25C, CL = 1nF TA = 25C, CL = 1nF TA = 25C, CL = 1nF TA = 25C, CL = 1nF 10 5.5 TR TF TR TF Pulse Width Modulator Maximum Duty Cycle Maximum Duty Cycle Minimum Duty Cycle Supply Current Start-Up Current ICC 1.0 0.5 A 40 30 20 15 0 70 50 50 40 ns ns ns ns mA 15.5 9.0 10 8.2 V IMP38C42/4, IMP38HC42/4 IMP38C43/5, IMP38HC43/5 IMP38C42/4, IMP38HC42/4 IMP38C43/5, IMP38HC43/5 13.5 7.8 8 7.0 14.5 8.4 9 7.6 IMP38C42/3, IMP38HC42/3, IMP38C44/5, IMP38HC44/5 94 48 96 50 VCC = 13V for IMP38C42/44, IMP38HC42/44 VCC = 7.5V for IMP38C43/45, IMP38HC43/45 VFB = VIS = 0 Note 1. Guaranteed by design. Not 100% tested in production. Note 2. Measured at trip point of VFB = 0V. Note 3. Gain is defined as: A= - 2.0 65 RDS (ON) Minimum Operating Voltage Operating Current Conditions V 0 % % % 95 120 A 0.5 1.5 mA Note 4. Adjust VCC above the start threshold before setting at 15V. Note 5. Output frequency equals the oscillator frequency for IMP38C42/3 and IMP38HC42/3 devices. Output frequency equals one-half the oscillator frequency for IMP38C44/5 and IMP38HC44/5 devices. VCOMP , 0 VCS 0.8V VCS Table 1. Startup and Operating Voltage Selection Guide Duty Cycle 0% to 96% 0% to 50% UVLO Thresholds Start-up at 8.4V Start-up at 14.5V Operating Minimum = 7.6V Operating Minimum = 9.0V IMP38C43/HC43 IMP38C45/HC45 IMP38C42/HC42 IMP38C44/HC44 38C/HC_t03.eps (c) 2000 IMP, Inc. PWM Controllers 5 IMP38C/HC/42/3/4/5 Application Information The IMP38C and IMP38HC devices are compatible with generic 384x PWM devices. The following discussion highlights the differences and advantages of the IMP `C' and `HC' designs. Start-up Current IMP's BiCMOS process allows for substantial reduction in the start-up current. Typical start-up current is 95A, with a maximum limit of 120A. Low start-up current allows high resistance, lower-wattage, start-up resistors to supply controller start-up power. Transient Protection Good high-frequency layout practices should be followed. Avoid long printed-circuit traces and component leads. Locate oscillator and compensation components near the IC. Avoid capacitive and inductive coupling of the switching waveform into the high-impedance inputs of the error amplifier, oscillator, and current-sense amplifier. VREF and VCC stability will be aided by using high-frequency decoupling capacitors. Undervoltage Lockout Several different thresholds are available. Operating Current Operating current has been reduced to 1.5mA maximum. Compared to the 11mA needed for a typical bipolar controller and 6mA for competitive BiCMOS controllers, IMP's low operating current allows the controller to run cooler and with better efficiency. In addition, the VCC hold-up capacitance (used during start-up) can be reduced. Output Driver The IMP38HC4x/38C4x CMOS output stage drives external power MOSFETs to the full supply voltage. Low ON-resistance and high peak current drive combine to give greater than 1000pF gate capacitance drive capability. Rise and fall time requirements may dictate the appropriate value of output capacitance. Within the restrictions of output capacity and controller power dissipation, switching frequencies can exceed 1MHz. The CMOS output stage "break-before-make" action is guaranteed by design and insures that no cross-conduction current will flow. This minimizes heat dissipation, increases efficiency and enhances reliability. Oscillator Operation Two external components, RT and CT, set the switching frequency. Undervoltage Lockout Thresholds Start-up at 8.4V Operating Minimum = 7.6V Start-up at 14.5V Operating Minimum = 9.0V IMP38C43/HC43 IMP38C45/HC45 IMP38C42/HC42 IMP38C44/HC44 38C/HC_t04.eps Under-voltage lockout (UVL) performance has been improved. When the power supply voltage is below the startup voltage, internal circuitry puts the output into a low impedance state and sets the output to zero. The output will sink up to 20mA in this controlled state and remain below 1.3V, well below the turn-on threshold voltage of the external MOSFET. With the IMP38C/HC4x output stage design, leakage current from the external power MOSFETs will not force the PWM output to rise and turn the external MOSFET on. Even when VDD drops to zero volts, the OUT pin will not rise above approximately 1.3V because the UVLO circuit is powered through the OUT pin. The IMP output stage performance in UVL mode, while sinking 20mA, is shown in Figure 2. With VCC = 14V, RT = 10k and CT = 3.3nF, nominal switching frequency is 50kHz. VOUT While Sinking 20mA 2.0 IMP38C/HC4x VREF frequency [ Hz ] = 1.73 RT [] x CT [ F ] 1.5 RT RT/CT CT Output (V) IMP38C4x IMP38HC4x 1.0 0.5 GND 38C/HC_07.eps 0 Figure 1. Oscillator Component Selection 0 1 2 3 4 5 VDD (V) 6 7 8 9 38C/HC_05b.eps Figure 2. Output Stage Performance in UVL Mode 6 408-432-9100/www.impweb.com (c) 2000 IMP, Inc. !S IMP38C/HC/42/3/4/5 Application Information (11) VD + UVLO - + - 6 (10) 2R - 1V R COMP T Q S Q OUT UVL Protection R + (8) PGND Connection Notes 3 (5) IMP38C4X, IMP38HC4X (8-Pin Devices) GND 5 AGND (9) 50% Maximum Duty Cycle: IMP38C44, IMP38HC44, IMP38C45, IMP38HC45 ISNS 96% Maximum Duty Cycle: IMP38C42, IMP38HC42, IMP38C43, IMP38HC43 ( ) Pins Are 14-Pin Devices Only 38C/HC_06.eps Figure 3. UVL Protection Circuit (c) 2000 IMP, Inc. PWM Controllers 7 IMP38C/HC/42/3/4/5 Package Dimensions SO (8-Pin) Inches a + L D C D A e 0.10mm 0.004in Max A A1 A2 b C D e E E1 L a ----- 0.0433 0.0020 0.0059 0.0295 0.0374 0.0098 0.0157 0.0051 0.0091 0.1142 0.1220 0.0256 BSC 0.193 BSC 0.1142 0.1220 0.0157 0.0276 0 6 SO (8-Pin) 0- 8 L E Max H ---- 1.10 0.050 0.15 0.75 0.95 0.25 0.40 0.13 0.23 2.90 3.10 0.65 BSC 4.90 BSC 2.90 3.10 0.40 0.70 0 6 SO (8-Pin)** MicroSO (8-Pin).eps A1 b Min MicroSO (8-Pin)* E1 E A2 Millimeters Min A A1 B C e E H L D 0.053 0.004 0.013 0.007 0.069 0.010 0.020 0.010 1.35 0.10 0.33 0.19 0.157 0.244 0.050 0.197 3.80 5.80 0.40 4.80 0.050 0.150 0.228 0.016 0.189 1.75 0.25 0.51 0.25 1.27 4.00 6.20 1.27 2.00 Plastic DIP (8-Pin)*** C D A e B A1 SO (8-Pin).eps Plastic DIP (8-Pin) D1 E D E1 A A2 L A1 A ----- 0.210 A1 0.015 ----- A2 0.115 0.195 b 0.014 0.022 b2 0.045 0.070 b3 0.030 0.045 D 0.355 0.400 D1 0.005 ----- E 0.300 0.325 E1 0.240 0.280 e 0.100 ----- eA 0.300 ----- eB ----- 0.430 eC ----- 0.060 L 0.115 0.150 * JEDEC Drawing MO-187AA ** JEDEC Drawing MS-112AA *** JEDEC Drawing MS-001BA ---- 0.38 2.92 0.36 1.14 0.80 9.02 0.13 7.62 6.10 5.33 ----- 4.95 0.56 1.78 1.14 10.16 ----- 8.26 7.11 2.54 7.62 ----- 10.92 2.92 3.81 38C/HC_t05.at3 0-15 e C b2 b eA eB Plastic DIP (8-Pin)a.eps 8 408-432-9100/www.impweb.com (c) 2000 IMP, Inc. !S IMP38C/HC/42/3/4/5 Package Dimensions SO (14-Pin) Inches Millimeters Min Max 0.0926 0.0040 0.013 0.0091 0.3465 0.214 0.1043 0.118 0.020 0.0125 0.3622 0.2992 Min Max 2.35 0.10 0.33 0.23 8.80 7.40 2.65 0.30 0.51 0.32 9.20 7.60 SO (14-Pin)* E A A1 B C D E H D 0- 8 A C e L B A1 SO (16-Pin).eps D1 E D A A1 e1 B1 B L H L 0.050 BSC 0.394 0.016 1.27 BSC 0.419 0.050 10.00 0.40 10.65 1.27 Plastic DIP (14-Pin)** A 0.155 0.200 A1 0.20 0.50 B 0.014 0.020 B1 0.050 0.065 C 0.008 0.012 D 0.745 0.770 E 0.300 0.325 E1 0.240 0.260 e1 0.100 TYP eA 0.300 TYP L 0.100 ----- * JEDEC Drawing MS-013 AF ** JEDEC Drawing MO-001 AA-AB Plastic DIP (14-Pin) E1 e 3.94 0.51 0.356 1.27 0.204 18.93 7.62 6.10 5.08 1.27 0.508 1.65 0.304 19.55 8.25 6.60 2.54 TYP 7.62 TYP 3.18 3.81 38C/HC_t06.at3 0-15 C eA Plastic DIP (14-Pin).eps (c) 2000 IMP, Inc. PWM Controllers 9 IMP38C/HC/42/3/4/5 IMP, Inc. Corporate Headquarters 2830 N. First Street San Jose, CA 95134-2071 Tel: 408-432-9100 Fax: 408-434-0335 e-mail: info@impinc.com http://www.impweb.com The IMP logo is a registered trademark of IMP, Inc. All other company and product names are trademarks of their respective owners. (c) 2000 IMP, Inc. Printed in USA Publication #: 3001 Revision: D Issue Date: 08/30/00 Type: Preliminary