1 TC429 6A SINGLE HIGH-SPEED, CMOS POWER MOSFET DRIVER 2 FEATURES GENERAL DESCRIPTION ■ ■ ■ ■ The TC429 is a high-speed, single CMOS-level translator and driver. Designed specifically to drive highly capacitive power MOSFET gates, the TC429 features 2.5Ω output impedance and 6A peak output current drive. A 2500pF capacitive load will be driven 18V in 25nsec. Delay time through the device is 60nsec. The rapid switching times with large capacitive loads minimize MOSFET transition power loss. A TTL/CMOS input logic level is translated into an output voltage swing that equals the supply and will swing to within 25mV of ground or VDD. Input voltage swing may equal the supply. Logic input current is under 10µA, making direct interface to CMOS/bipolar switch-mode power supply controllers easy. Input "speed-up" capacitors are not required. The CMOS design minimizes quiescent power supply current. With a logic 1 input, power supply current is 5mA maximum and decreases to 0.5mA for logic 0 inputs. For dual devices, see the TC426/TC427/TC428 data sheet. For noninverting applications, or applications requiring latch-up protection, see the TC4420/TC4429 data sheet. ■ ■ ■ ■ High Peak Output Current .................................. 6A Wide Operating Range ............................. 7V to 18V High-Impedance CMOS Logic Input Logic Input Threshold Independent of Supply Voltage Low Supply Current — With Logic 1 Input ................................ 5mA Max — With Logic 0 Input ............................. 0.5mA Max Output Voltage Swing Within 25 mV of Ground or VDD Short Delay Time .................................. 75nsec Max High Capacitive Load Drive Capability — tRISE, tFALL = 35nsec Max With CLOAD = 2500pF APPLICATIONS ■ ■ ■ ■ Switch-Mode Power Supplies CCD Drivers Pulse Transformer Drive Class D Switching Amplifiers PIN CONFIGURATION VDD 1 8 VDD INPUT 2 7 OUTPUT NC 3 6 OUTPUT GND 4 TC429 5 ORDERING INFORMATION GND NC = NO INTERNAL CONNECTION NOTE: Duplicate pins must both be connected for proper operation. Part No. Package TC429CPA TC429EPA TC429MJA 8-Pin Plastic DIP 8-Pin Plastic DIP 8-Pin CerDIP 3 4 5 Temperature Range 0°C to +70°C – 40°C to +85°C – 55°C to +125°C 6 TYPICAL APPLICATION 1,8 VDD 300mV 6,7 INPUT 7 OUTPUT 2 TC429 GND 4,5 EFFECTIVE INPUT C = 38pF 8 TC429-4 10/11/96 TELCOM SEMICONDUCTOR, INC. 4-175 6A SINGLE HIGH-SPEED, CMOS POWER MOSFET DRIVER TC429 ABSOLUTE MAXIMUM RATINGS* Supply Voltage ......................................................... +20V Input Voltage, Any Terminal ..... VDD +0.3V to GND – 0.3V Power Dissipation (TA ≤ 70°C) Plastic DIP ......................................................730mW CerDIP ............................................................800mW Derating Factors Plastic DIP ............................ 5.6 mW/°C Above 36°C CerDIP ...................................................... 6.4 mW/°C Operating Temperature Range C Version ............................................... 0°C to +70°C I Version ........................................... – 25°C to +85°C E Version .......................................... – 40°C to +85°C M Version ....................................... – 55°C to +125°C ELECTRICAL CHARACTERISTICS: Symbol Parameter Maximum Chip Temperature ................................. +150°C Storage Temperature Range ................ – 65°C to +150°C Lead Temperature (Soldering, 10 sec) ................. +300°C *Static-sensitive device. Unused devices must be stored in conductive material. Protect devices from static discharge and static fields. Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only and functional operation of the device at these or any other conditions above those indicated in the operational sections of the specifications is not implied. Exposure to Absolute Maximum Rating Conditions for extended periods may affect device reliability. TA = +25°C with 7V ≤ VDD ≤ 18V, unless otherwise specified. Test Conditions Min Typ Max Unit 0V ≤ VIN ≤ VDD 2.4 — – 10 1.8 1.3 — — 0.8 10 V V µA VDD – 0.025 — — — — 1.8 — 0.025 2.5 V V Ω — 1.5 2.5 — 6 — A Input VIH VIL IIN Logic 1, High Input Voltage Logic 0, Low Input Voltage Input Current Output VOH VOL RO IPK High Output Voltage Low Output Voltage Output Resistance Peak Output Current VIN = 0.8V, IOUT = 10mA, VDD = 18V VIN = 2.4V, IOUT = 10mA, VDD = 18V VDD = 18V (See Figure 3) Switching Time (Note 1) tR tF tD1 tD2 Rise Time Fall Time Delay Time Delay Time Figure 1, CL = 2500pF Figure 1, CL = 2500pF Figure 1 Figure 1 — — — — 23 25 53 60 35 35 75 75 nsec nsec nsec nsec Power Supply Current VIN = 3V — 3.5 5 mA VIN = 0V — 0.3 0.5 Power Supply IS NOTES: 1. Switching times guaranteed by design. 4-176 TELCOM SEMICONDUCTOR, INC. 6A SINGLE HIGH-SPEED, CMOS POWER MOSFET DRIVER 1 TC429 ELECTRICAL CHARACTERISTICS: Over operating temperature with 7V ≤ VDD ≤ 18V, unless otherwise specified. Symbol Parameter Unit Min Typ Max 0V ≤ VIN ≤ VDD 2.4 — – 10 — — — — 0.8 10 V V µA VDD – 0.025 — — — — — — 0.025 5 V V Ω 3 — — 5 Figure 1, CL = 2500pF Figure 1, CL = 2500pF Figure 1 Figure 1 — — — — — — — — 70 70 100 120 nsec nsec nsec nsec 4 VIN = 3V — — 12 mA VIN = 0V — — 1 Input VIH VIL IIN Logic 1, High Input Voltage Logic 0, Low Input Voltage Input Current 2 Test Conditions Output VOH VOL RO High Output Voltage Low Output Voltage Output Resistance VIN = 0.8V, IOUT = 10 mA, VDD = 18V VIN = 2.4V, IOUT = 10 mA, VDD = 18V Switching Time (Note 1) tR tF tD1 tD2 Rise Time Fall Time Delay Time Delay Time Power Supply IS Power Supply Current NOTE: 1. Switching times guaranteed by design. SWITCHING SPEED 5 VDD = 18V 1 µF 1 INPUT 0.1 µF 8 2 6 6 OUTPUT 7 CL= 2500 pF TC429 4 5 INPUT: 100 kHz, square wave tRISE = tFALL ≤ 10 nsec +5V 7 90% INPUT 0V 18V 10% tD1 tF tD2 tR 90% 90% OUTPUT 0V 10% 10% 8 Figure 1. Inverting Driver Switching Time Test Circuit TELCOM SEMICONDUCTOR, INC. 4-177 6A SINGLE HIGH-SPEED, CMOS POWER MOSFET DRIVER TC429 SUPPLY BYPASSING Charging and discharging large capacitive loads quickly requires large currents. For example, charging a 2500 pF load 18V in 25nsec requires a 1.8A current from the device's power supply. To guarantee low supply impedance over a wide frequency range, a parallel capacitor combination is recommended for supply bypassing. Low-inductance ceramic disk capacitors with short lead lengths (<0.5 in.) should be used. A 1 µF film capacitor in parallel with one or two 0.1 µF ceramic disk capacitors normally provides adequate bypassing. GROUNDING The high-current capability of the TC429 demands careful PC board layout for best performance. Since the TC429 is an inverting driver, any ground lead impedance will appear as negative feedback which can degrade switching speed. The feedback is especially noticeable with slow risetime inputs, such as those produced by an open-collector output with resistor pull-up. The TC429 input structure includes about 300 mV of hysteresis to ensure clean transitions and freedom from oscillation, but attention to layout is still recommended. Figure 2 shows the feedback effect in detail. As the TC429 input begins to go positive, the output goes negative and several amperes of current flow in the ground lead. As little as 0.05Ω of PC trace resistance can produce hundreds of millivolts at the TC429 ground pins. If the driving logic is referenced to power ground, the effective logic input level is reduced and oscillations may result. +18V 1 µF TC429 2.4V 0V 0.1 µF 18V 1 8 6,7 2 5 4 TEK CURRENT PROBE 6302 0V 0.1 µF 2500 pF LOGIC GROUND 300 mV 6A PC TRACE RESISTANCE = 0.05Ω POWER GROUND Figure 2. Switching Time Degradation Due to Negative Feedback 4-178 To ensure optimum device performance, separate ground traces should be provided for the logic and power connections. Connecting logic ground directly to the TC429 GND pins ensures full logic drive to the input and fast output switching. Both GND pins should be connected to power ground. INPUT STAGE The input voltage level changes the no-load or quiescent supply current. The N-channel MOSFET input stage transistor drives a 3 mA current source load. With a logic "1" input, the maximum quiescent supply current is 5 mA. Logic "0" input level signals reduce quiescent current to 500 µA maximum. The TC429 input is designed to provide 300 mV of hysteresis, providing clean transitions and minimizing output stage current spiking when changing states. Input voltage levels are approximately 1.5V, making the device TTL compatible over the 7V to 18V operating supply range. Input current is less than 10µA over this range. The TC429 can be directly driven by TL494, SG1526/ 1527, SG1524, SE5560 or similar switch-mode power supply integrated circuits. By off-loading the power-driving duties to the TC429, the power supply controller can operate at lower dissipation, improving performance and reliability. POWER DISSIPATION CMOS circuits usually permit the user to ignore power dissipation. Logic families such as the 4000 and 74C have outputs that can only supply a few milliamperes of current, and even shorting outputs to ground will not force enough current to destroy the device. The TC429, however, can source or sink several amperes and drive large capacitive loads at high frequency. The package power dissipation limit can easily be exceeded. Therefore, some attention should be given to power dissipation when driving low impedance loads and/or operating at high frequency. The supply current versus frequency and supply current versus capacitive load characteristic curves will aid in determining power dissipation calculations. Table I lists the maximum operating frequency for several power supply voltages when driving a 2500pF load. More accurate power dissipation figures can be obtained by summing the three power sources. Input signal duty cycle, power supply voltage, and capacitive load influence package power dissipation. Given power dissipation and package thermal resistance, the maximum ambient operation temperature is easily calculated. The 8-pin CerDIP junction-to-ambient thermal resistance is 150°C/W. At +25°C, the package is rated at 800 mW maximum dissipation. Maximum allowable chip temperature is +150°C. TELCOM SEMICONDUCTOR, INC. 6A SINGLE HIGH-SPEED, CMOS POWER MOSFET DRIVER 1 TC429 NOTE: Ambient operating temperature should not exceed +85°C for IJA devices or +125°C for MJA devices. TELCOM SEMICONDUCTOR, INC. Table 1. Maximum Operating Frequencies VS fMax 18V 15V 10V 5V 500 kHz 700 kHz 1.3 MHz >2 MHz 2 CONDITIONS: 1. CerDIP Package (θJA = 150°C/W) 2. TA = +25°C 3. C L = 2500 pF 3 Thermal Derating Curves 1600 1400 MAX. POWER (mV) Three components make up total package power dissipation: (1) Capacitive load dissipation (PC) (2) Quiescent power (PQ) (3) Transition power (PT) The capacitive load-caused dissipation is a direct function of frequency, capacitive load, and supply voltage. The package power dissipation is: PC = f C VS2, where: f = Switching frequency C = Capacitive load VS = Supply voltage. Quiescent power dissipation depends on input signal duty cycle. A logic low input results in a low-power dissipation mode with only 0.5 mA total current drain. Logic high signals raise the current to 5 mA maximum. The quiescent power dissipation is: PQ = VS (D (IH) + (1–D) IL), where: IH = Quiescent current with input high (5 mA max) IL = Quiescent current with input low (0.5 mA max) D = Duty cycle. Transition power dissipation arises because the output stage N- and P-channel MOS transistors are ON simultaneously for a very short period when the output changes. The transition package power dissipation is approximately: PT = f VS (3.3 x 10–9 A · Sec). An example shows the relative magnitude for each item. Example 1: C = 2500 pF VS = 15V D = 50% f = 200 kHz PD = Package power dissipation = PC + PT + PQ = 113 mW + 10 mW + 41 mW = 164 mW. Maximum operating temperature = TJ – θJA (PD) = 125°C, where: TJ = Maximum allowable junction temperature (+150°C) θJA = Junction-to-ambient thermal resistance (150°C/W, CerDIP). 8 Pin DIP 1200 8 Pin CerDIP 1000 4 800 8 Pin SOIC 600 400 200 0 0 10 20 30 40 50 60 70 80 90 100 110 120 AMBIENT TEMPERATURE (°C) 5 Peak Output Current Capability 6 POWER-ON OSCILLATION It is extremely important that all MOSFET DRIVER applications be evaluated for the possibility of having HIGH-POWER OSCILLATIONS occurring during the POWER-ON cycle. POWER-ON OSCILLATIONS are due to trace size and layout as well as component placement. A ‘quick fix’ for most applications which exhibit POWER-ON OSCILLATION problems is to place approximately 10 kΩ in series with the input of the MOSFET driver. 4-179 7 8 6A SINGLE HIGH-SPEED, CMOS POWER MOSFET DRIVER TC429 TYPICAL CHARACTERISTICS TIME (nsec) 40 30 tF 20 40 tF 30 10 15 SUPPLY VOLTAGE (V) 10 20 Supply Current vs. Capacitive Load 80 40 30 400kHz 20 200kHz 10 1K CAPACITIVE LOAD (pF) Delay Times vs. Supply Voltage CL = 2500pF VDD = +15V 70 tD2 60 TA = +25°C CL = 2500pF 120 100 80 tD2 tD1 50 60 20kHz 100 1K CAPACITIVE LOAD (pF) 40 10K Supply Current vs. Frequency 4 TA = +25°C CL = 2500 pF SUPPLY CURRENT (mA) 10V 40 15V 30 VDD = 18V 20 40 –50 –25 0 25 50 75 100 125 150 TEMPERATURE (°C) 10 TA = +25°C RL = ∞ INPUT LOGIC "1" tD1 5 10 15 SUPPLY VOLTAGE (V) VDD = +18°C RL = ∞ INPUT LOGIC "1" 4 2 20 Supply Current vs. Temperature Supply Current vs. Supply Voltage 50 10K 140 DELAY TIME (nsec) TA = +25°C VDD = +15V DELAY TIME (nsec) SUPPLY CURRENT (mA) 1 100 –50 –25 0 25 50 75 100 125 150 TEMPERATURE (°C) 90 50 0 10 tR tR 10 Delay Times vs. Temperature 70 60 tF 20 tR 5 TA = +25°C VDD = +15V SUPPLY CURRENT (mA) TIME (nsec) 50 CL = 2500pF VDD = +15V TIME (nsec) TA = +25°C CL = 2500pF 50 SUPPLY CURRENT (mA) 100 60 60 10 Rise/Fall Times vs. Capacitive Load Rise/Fall Times vs. Temperature Rise/Fall Times vs. Supply Voltage 3 5V 1 10 100 FREQUENCY (kHz) 1K 300mV 10 200mV 5 0.25 0.50 0.75 1 1.25 1.50 1.75 2 INPUT VOLTAGE (V) OUTPUT VOLTAGE (mV) OUTPUT VOLTAGE (V) TA = +25°C 15 0 4-180 400 HYSTERESIS '310mV 4 8 12 16 SUPPLY VOLTAGE (V) 20 2 –75 –50 –25 0 25 50 75 100 125 150 TEMPERATURE (°C) High Output Voltage vs. Current Voltage Transfer Characteristics 20 0 TA = +25°C 300 VDD = 5V 200 100 0 Low Output Voltage vs. Current 400 10V 15V 18V 20 40 60 80 CURRENT SOURCED (mA) 100 OUTPUT VOLTAGE (mV) 0 TA = +25°C 300 VDD = 5V 200 10V 15V 100 18V 0 20 40 60 80 CURRENT SUNK (mA) 100 TELCOM SEMICONDUCTOR, INC. 6A SINGLE HIGH-SPEED, CMOS POWER MOSFET DRIVER 1 TC429 +18V 2 1µF 18V 2.4V 1 8 6,7 2 0V 0.1µF 5 4 TEK CURRENT PROBE 6302 0V 0.1µF 3 2500pF TC429 Figure 3. Peak Output Current Test Circuit 4 5 6 7 8 TELCOM SEMICONDUCTOR, INC. 4-181