6A SINGLE HIGH-SPEED, CMOS POWER MOSFET DRIVER
1
TC429
FEATURES
■ 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 V
DD
■ Short Delay Time .................................. 75nsec Max
■ High Capacitive Load Drive Capability
— t
RISE
, t
= 35nsec Max With C
FALL
LOAD
= 2500pF
APPLICATIONS
■ Switch-Mode Power Supplies
■ CCD Drivers
■ Pulse Transformer Drive
■ Class D Switching Amplifiers
PIN CONFIGURATION
V
18
DD
27
INPUT
36
NC
45
NC = NO INTERNAL CONNECTION
NOTE: Duplicate pins must both be connected for proper operation.
TYPICAL APPLICATION
TC429
V
DD
OUTPUT
OUTPUT
GNDGND
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.
ORDERING INFORMATION
Temperature
Part No. Package Range
TC429CPA 8-Pin Plastic DIP 0°C to +70°C
TC429EPA 8-Pin Plastic DIP – 40°C to +85°C
TC429MJA 8-Pin CerDIP – 55°C to +125°C
1,8
V
DD
2
3
4
5
6
INPUT
GND
TELCOM SEMICONDUCTOR, INC.
2
4,5
EFFECTIVE
INPUT
C = 38pF
300mV
TC429
6,7
OUTPUT
7
8
TC429-4 10/11/96
4-175
TC429
6A SINGLE HIGH-SPEED,
CMOS POWER MOSFET DRIVER
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
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.
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: T
= +25°C with 7V ≤ VDD ≤ 18V, unless otherwise specified.
A
Symbol Parameter Test Conditions Min Typ Max Unit
Input
V
IH
V
IL
I
IN
Logic 1, High Input Voltage 2.4 1.8 — V
Logic 0, Low Input Voltage — 1.3 0.8 V
Input Current 0V ≤ VIN ≤ V
DD
– 10 — 10 µA
Output
V
OH
V
OL
R
O
I
PK
High Output Voltage V
– 0.025 — — V
DD
Low Output Voltage — — 0.025 V
Output Resistance VIN = 0.8V, — 1.8 2.5 Ω
I
= 10mA, VDD = 18V
OUT
VIN = 2.4V, — 1.5 2.5
I
= 10mA, VDD = 18V
OUT
Peak Output Current VDD = 18V (See Figure 3) — 6 — A
Switching Time (Note 1)
t
R
t
F
t
D1
t
D2
Rise Time Figure 1, CL = 2500pF — 23 35 nsec
Fall Time Figure 1, CL = 2500pF — 25 35 nsec
Delay Time Figure 1 — 53 75 nsec
Delay Time Figure 1 — 60 75 nsec
Power Supply
I
S
NOTES: 1. Switching times guaranteed by design.
Power Supply Current VIN = 3V — 3.5 5 mA
VIN = 0V — 0.3 0.5
4-176
TELCOM SEMICONDUCTOR, INC.
6A SINGLE HIGH-SPEED,
CMOS POWER MOSFET DRIVER
1
TC429
ELECTRICAL CHARACTERISTICS: Over operating temperature with 7V ≤ V
Symbol Parameter Test Conditions Min Typ Max Unit
Input
V
IH
V
IL
I
IN
Output
V
OH
V
OL
R
O
Switching Time (Note 1)
t
R
t
F
t
D1
t
D2
Power Supply
I
S
NOTE: 1. Switching times guaranteed by design.
Logic 1, High Input Voltage 2.4 — — V
Logic 0, Low Input Voltage — — 0.8 V
Input Current 0V ≤ VIN ≤ V
High Output Voltage V
Low Output Voltage — — 0.025 V
Output Resistance VIN = 0.8V, — — 5 Ω
I
= 10 mA, VDD = 18V
OUT
V
= 2.4V, — — 5
IN
I
= 10 mA, VDD = 18V
OUT
Rise Time Figure 1, CL = 2500pF — — 70 nsec
Fall Time Figure 1, CL = 2500pF — — 70 nsec
Delay Time Figure 1 — — 100 nsec
Delay Time Figure 1 — — 120 nsec
Power Supply Current VIN = 3V — — 12 mA
VIN = 0V — — 1
DD
≤ 18V, unless otherwise specified.
DD
– 10 — 10 µA
– 0.025 — — V
DD
SWITCHING SPEED
VDD = 18V
2
3
4
5
18
INPUT
INPUT
OUTPUT
26
7
TC429
45
INPUT: 100 kHz, square wave
t
RISE
+5V
10%
0V
18V
0V
Figure 1. Inverting Driver Switching Time Test Circuit
TELCOM SEMICONDUCTOR, INC.
t
D1
90% 90%
t
90%
t
D2
F
0.1 µF 1 µF
OUTPUT
C
= 2500 pF
L
= t
10%10%
FALL
t
R
≤ 10 nsec
6
7
8
4-177
TC429
6A SINGLE HIGH-SPEED,
CMOS POWER MOSFET DRIVER
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
TC429
2.4V
0V
LOGIC
GROUND
300 mV
POWER
GROUND
Figure 2. Switching Time Degradation Due to Negative Feedback
4-178
1
2
8
5
4
1 µF
18V
TEK CURRENT
PROBE 6302
6,7
0.1 µF0.1 µF
6A
PC TRACE RESISTANCE = 0.05Ω
0V
2500 pF
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
Three components make up total package power dissi-
pation:
(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 V
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
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 + P
= 113 mW + 10 mW + 41 mW
= 164 mW.
Maximum operating temperature = TJ – θJA (PD)
where: TJ= Maximum allowable junction temperature
(+150°C)
θJA= Junction-to-ambient thermal resistance
(150°C/W, CerDIP).
NOTE: Ambient operating temperature should not exceed +85°C for
IJA devices or +125°C for MJA devices.
2
,
S
–9
A · Sec).
Q
= 125°C,
Table 1. Maximum Operating Frequencies
V
S
18V 500 kHz
15V 700 kHz
10V 1.3 MHz
5V >2 MHz
CONDITIONS: 1. CerDIP Package (θJA = 150°C/W)
1600
1400
1200
1000
800
600
400
MAX. POWER (mV)
200
0
0
2. TA = +25°C
3. CL = 2500 pF
Thermal Derating Curves
8 Pin DIP
8 Pin CerDIP
8 Pin SOIC
10 20
30 40
Peak Output Current Capability
50 60
AMBIENT TEMPERATURE (°C)
f
Max
70
80 90 100 110 120
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.
2
3
4
5
6
7
8
TELCOM SEMICONDUCTOR, INC.
4-179
TC429
TYPICAL CHARACTERISTICS
Rise/Fall Times vs. Supply Voltage
60
TA = +25°C
CL = 2500pF
50
40
30
TIME (nsec)
Rise/Fall Times vs. Temperature
60
CL = 2500pF
VDD = +15V
50
40
30
TIME (nsec)
tF
6A SINGLE HIGH-SPEED,
CMOS POWER MOSFET DRIVER
Rise/Fall Times vs. Capacitive Load
100
TA = +25
°C
V
= +15V
DD
tF
t
tF
10
t
R
TIME (nsec)
R
20
10
5101520
SUPPLY VOLTAGE (V)
Supply Current vs. Capacitive Load
70
TA = +25°C
V
60
50
40
30
20
SUPPLY CURRENT (mA)
10
0
= +15V
DD
400kHz
200kHz
20kHz
10 100 1K 10K
CAPACITIVE LOAD (pF)
t
R
Supply Current vs. Frequency
50
TA = +25°C
CL = 2500 pF
40
30
20
VDD = 18V
10V
15V
20
10
–50 –25 25 50 100 125 150
075
TEMPERATURE (
°C)
Delay Times vs. Temperature
90
CL = 2500pF
V
= +15V
DD
80
70
t
60
DELAY TIME (nsec)
50
40
–50 –25 25 50 100 125
D2
t
D1
075
TEMPERATURE (°C)
Supply Current vs. Supply Voltage
4
TA = +25
°C
RL = ∞
INPUT LOGIC "1"
2
1
100 1K 10K
CAPACITIVE LOAD (pF)
Delay Times vs. Supply Voltage
140
TA = +25°C
CL = 2500pF
120
100
80
DELAY TIME (nsec)
60
40
150
5
10 15 20
SUPPLY VOLTAGE (V)
Supply Current vs. Temperature
4
3
VDD = +18
RL = ∞
INPUT LOGIC "1"
t
D2
t
D1
°C
4-180
10
SUPPLY CURRENT (mA)
0
1 10 100 1K
FREQUENCY (kHz)
Voltage Transfer Characteristics
20
TA = +25°C
15
10
5
OUTPUT VOLTAGE (V)
0.25 0.50 0.75 1 1.50 1.75 2
0
INPUT VOLTAGE (V)
HYSTERESIS
'310mV
300mV
200mV
1.25
SUPPLY CURRENT (mA)
5V
048121620
High Output Voltage vs. Current
400
TA = +25°C
300
200
100
OUTPUT VOLTAGE (mV)
0 20 40 60 80 100
SUPPLY VOLTAGE (V)
VDD = 5V
10V
CURRENT SOURCED (mA)
18V
SUPPLY CURRENT (mA)
2
–75 –25 50 100
400
300
15V
200
100
OUTPUT VOLTAGE (mV)
–50 0 25 75 125
TEMPERATURE (°C)
150
Low Output Voltage vs. Current
TA = +25°C
VDD = 5V
10V
15V
18V
0 20 40 60 80 100
CURRENT SUNK (mA)
TELCOM SEMICONDUCTOR, INC.
6A SINGLE HIGH-SPEED,
CMOS POWER MOSFET DRIVER
+18V
2.4V
0V
2
Figure 3. Peak Output Current Test Circuit
1
TC429
2
1µF
18V
1
8
5
4
TEK CURRENT
PROBE 6302
6,7
0.1µF0.1µF
0V
2500pF
3
TC429
4
5
6
TELCOM SEMICONDUCTOR, INC.
7
8
4-181
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