Document Outline
- Return to Contents
- List of Figures
- 1. Inverting Driver Switching Time Test Circuit
- 2. Switching Time Degradation Due to Negative Feedback
- 3. Peak Output Current Test Circuit
- List of Tables
- 1. Maximum Operating Frequencies
- Features
- Applications
- Pin Configuration
- Typical Application
- General Description
- Ordering Information
- Absolute Maximum Ratings*
- Electrical Characteristics: TA = +25C with 7V VDD 18V, unless otherwise specified.
- Electrical Characteristics: Over operating temperature with 7V VDD 18V, unless otherwise specified.
- Switching Speed
- Supply Bypassing
- Grounding
- Input Stage
- Power Dissipation
- Power-On Oscillation
- Typical Characteristics
4-175
TELCOM SEMICONDUCTOR, INC.
7
6
5
4
3
1
2
8
TC429
FEATURES
s
High Peak Output Current .................................. 6A
s
Wide Operating Range ............................. 7V to 18V
s
High-Impedance CMOS Logic Input
s
Logic Input Threshold Independent of
Supply Voltage
s
Low Supply Current
-- With Logic 1 Input ................................ 5mA Max
-- With Logic 0 Input ............................. 0.5mA Max
s
Output Voltage Swing Within 25 mV of Ground
or V
DD
s
Short Delay Time .................................. 75nsec Max
s
High Capacitive Load Drive Capability
-- t
RISE
, t
FALL
= 35nsec Max With C
LOAD
= 2500pF
APPLICATIONS
s
Switch-Mode Power Supplies
s
CCD Drivers
s
Pulse Transformer Drive
s
Class D Switching Amplifiers
GENERAL DESCRIPTION
The TC429 is a high-speed, single CMOS-level transla-
tor and driver. Designed specifically to drive highly capaci-
tive power MOSFET gates, the TC429 features 2.5
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 transi-
tion 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 V
DD
. Input voltage swing may
equal the supply. Logic input current is under 10
A, 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.
TYPICAL APPLICATION
NC = NO INTERNAL CONNECTION
1
8
2
7
3
6
4
5
TC429
GND
GND
NC
INPUT
VDD
OUTPUT
OUTPUT
VDD
NOTE: Duplicate pins must both be connected for proper operation.
PIN CONFIGURATION
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
OUTPUT
INPUT
GND
EFFECTIVE
INPUT
C = 38pF
VDD
300mV
2
4,5
1,8
6,7
TC429
TC429-4 10/11/96
6A SINGLE HIGH-SPEED, CMOS POWER MOSFET DRIVER
4-176
TELCOM SEMICONDUCTOR, INC.
ABSOLUTE MAXIMUM RATINGS*
Supply Voltage ......................................................... +20V
Input Voltage, Any Terminal ..... V
DD
+0.3V to GND 0.3V
Power Dissipation (T
A
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:
T
A
= +25
C with 7V
V
DD
18V, unless otherwise specified.
Symbol
Parameter
Test Conditions
Min
Typ
Max
Unit
Input
V
IH
Logic 1, High Input Voltage
2.4
1.8
--
V
V
IL
Logic 0, Low Input Voltage
--
1.3
0.8
V
I
IN
Input Current
0V
V
IN
V
DD
10
--
10
A
Output
V
OH
High Output Voltage
V
DD
0.025
--
--
V
V
OL
Low Output Voltage
--
--
0.025
V
R
O
Output Resistance
V
IN
= 0.8V,
--
1.8
2.5
I
OUT
= 10mA, V
DD
= 18V
V
IN
= 2.4V,
--
1.5
2.5
I
OUT
= 10mA, V
DD
= 18V
I
PK
Peak Output Current
V
DD
= 18V (See Figure 3)
--
6
--
A
Switching Time (Note 1)
t
R
Rise Time
Figure 1, C
L
= 2500pF
--
23
35
nsec
t
F
Fall Time
Figure 1, C
L
= 2500pF
--
25
35
nsec
t
D1
Delay Time
Figure 1
--
53
75
nsec
t
D2
Delay Time
Figure 1
--
60
75
nsec
Power Supply
I
S
Power Supply Current
V
IN
= 3V
--
3.5
5
mA
V
IN
= 0V
--
0.3
0.5
NOTES: 1. Switching times guaranteed by design.
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 perma-
nent 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.
TC429
6A SINGLE HIGH-SPEED,
CMOS POWER MOSFET DRIVER
4-177
TELCOM SEMICONDUCTOR, INC.
7
6
5
4
3
1
2
8
ELECTRICAL CHARACTERISTICS:
Over operating temperature with 7V
V
DD
18V, unless otherwise specified.
Symbol
Parameter
Test Conditions
Min
Typ
Max
Unit
Input
V
IH
Logic 1, High Input Voltage
2.4
--
--
V
V
IL
Logic 0, Low Input Voltage
--
--
0.8
V
I
IN
Input Current
0V
V
IN
V
DD
10
--
10
A
Output
V
OH
High Output Voltage
V
DD
0.025
--
--
V
V
OL
Low Output Voltage
--
--
0.025
V
R
O
Output Resistance
V
IN
= 0.8V,
--
--
5
I
OUT
= 10 mA, V
DD
= 18V
V
IN
= 2.4V,
--
--
5
I
OUT
= 10 mA, V
DD
= 18V
Switching Time (Note 1)
t
R
Rise Time
Figure 1, C
L
= 2500pF
--
--
70
nsec
t
F
Fall Time
Figure 1, C
L
= 2500pF
--
--
70
nsec
t
D1
Delay Time
Figure 1
--
--
100
nsec
t
D2
Delay Time
Figure 1
--
--
120
nsec
Power Supply
I
S
Power Supply Current
V
IN
= 3V
--
--
12
mA
V
IN
= 0V
--
--
1
NOTE:
1. Switching times guaranteed by design.
SWITCHING SPEED
Figure 1. Inverting Driver Switching Time Test Circuit
1
8
4
5
2
6
7
CL= 2500 pF
OUTPUT
0.1
F
1
F
INPUT
TC429
VDD = 18V
+5V
18V
OUTPUT
0V
0V
90%
10%
10%
10%
tD1
tD2
90%
90%
tR
tF
INPUT
INPUT: 100 kHz, square wave
tRISE = tFALL
10 nsec
TC429
6A SINGLE HIGH-SPEED,
CMOS POWER MOSFET DRIVER
4-178
TELCOM SEMICONDUCTOR, INC.
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 quies-
cent 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
A
maximum.
The TC429 input is designed to provide 300 mV of
hysteresis, providing clean transitions and minimizing out-
put stage current spiking when changing states. Input volt-
age levels are approximately 1.5V, making the device TTL
compatible over the 7V to 18V operating supply range. Input
current is less than 10
A over this range.
The TC429 can be directly driven by TL494, SG1526/
1527, SG1524, SE5560 or similar switch-mode power sup-
ply 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 cur-
rent 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 calcu-
lated. The 8-pin CerDIP junction-to-ambient thermal resis-
tance is 150
C/W. At +25
C, the package is rated at 800 mW
maximum dissipation. Maximum allowable chip tempera-
ture is +150
C.
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 fre-
quency range, a parallel capacitor combination is recom-
mended for supply bypassing. Low-inductance ceramic
disk capacitors with short lead lengths (<0.5 in.) should be
used. A 1
F film capacitor in parallel with one or two 0.1
F
ceramic disk capacitors normally provides adequate by-
passing.
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 rise-
time 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 transi-
tions 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 0.05
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.
TC429
1 F
0.1 F
0.1 F
0V
18V
2.4V
0V
LOGIC
GROUND
POWER
GROUND
300 mV
6A
PC TRACE RESISTANCE = 0.05
2500 pF
1
8
6,7
5
4
2
+18V
TEK CURRENT
PROBE 6302
Figure 2. Switching Time Degradation Due to Negative Feedback
TC429
6A SINGLE HIGH-SPEED,
CMOS POWER MOSFET DRIVER
4-179
TELCOM SEMICONDUCTOR, INC.
7
6
5
4
3
1
2
8
Table 1. Maximum Operating Frequencies
V
S
f
Max
18V
500 kHz
15V
700 kHz
10V
1.3 MHz
5V
>2 MHz
CONDITIONS: 1. CerDIP Package (
JA
= 150
C/W)
2. T
A
= +25
C
3. C
L
= 2500 pF
Three components make up total package power dissi-
pation:
(1) Capacitive load dissipation (P
C
)
(2) Quiescent power (P
Q
)
(3) Transition power (P
T
)
The capacitive load-caused dissipation is a direct func-
tion of frequency, capacitive load, and supply voltage. The
package power dissipation is:
P
C
= f C V
S
2
,
where: f = Switching frequency
C = Capacitive load
V
S
= Supply voltage.
Quiescent power dissipation depends on input signal
duty cycle. A logic low input results in a low-power dissipa-
tion mode with only 0.5 mA total current drain. Logic high
signals raise the current to 5 mA maximum. The quiescent
power dissipation is:
P
Q
= V
S
(D (I
H
) + (1D) I
L
),
where: I
H
= Quiescent current with input high (5 mA max)
I
L
= 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 simulta-
neously for a very short period when the output changes.
The transition package power dissipation is approximately:
P
T
= f V
S
(3.3 x 10
9
A Sec).
An example shows the relative magnitude for each item.
Example 1:
C = 2500 pF
V
S
= 15V
D = 50%
f
= 200 kHz
P
D
= Package power dissipation = P
C
+ P
T
+ P
Q
= 113 mW + 10 mW + 41 mW
= 164 mW.
Maximum operating temperature = T
J
JA
(P
D
)
= 125
C,
where: T
J
= Maximum allowable junction temperature
(+150
C)
JA
= 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.
Peak Output Current Capability
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 prob-
lems is to place approximately 10 k
in series with the input
of the MOSFET driver.
200
0
400
600
800
1000
1200
1400
1600
0
10
20
30
40
50
60
70
80
90
100
110
120
AMBIENT TEMPERATURE (
C)
MAX. POWER (mV)
8 Pin DIP
Thermal Derating Curves
8 Pin CerDIP
8 Pin SOIC
TC429
6A SINGLE HIGH-SPEED,
CMOS POWER MOSFET DRIVER
4-180
TELCOM SEMICONDUCTOR, INC.
TC429
6A SINGLE HIGH-SPEED,
CMOS POWER MOSFET DRIVER
TYPICAL CHARACTERISTICS
60
50
40
30
20
10
5
10
15
20
SUPPLY VOLTAGE (V)
TIME (nsec)
Rise/Fall Times vs. Supply Voltage
TA = +25
C
CL = 2500pF
60
50
40
30
20
10
0
75
TEMPERATURE (
C)
TIME (nsec)
Rise/Fall Times vs. Temperature
CL = 2500pF
VDD = +15V
50 25
25 50
100 125 150
tR
tR
tF
tF
100
10
1
100
1K
10K
CAPACITIVE LOAD (pF)
TIME (nsec)
Rise/Fall Times vs. Capacitive Load
90
80
70
60
50
40
0
75
TEMPERATURE (
C)
DELAY TIME (nsec)
Delay Times vs. Temperature
50 25
25 50
100 125
tD2
tD1
70
60
50
40
30
20
10
0
SUPPLY CURRENT (mA)
10
100
1K
10K
CAPACITIVE LOAD (pF)
200kHz
20kHz
Supply Current vs. Capacitive Load
tR
tF
TA = +25
C
VDD = +15V
400kHz
140
120
100
80
60
40
5
DELAY TIME (nsec)
Delay Times vs. Supply Voltage
10
15
20
SUPPLY VOLTAGE (V)
tD1
tD2
TA = +25
C
CL = 2500pF
TA = +25
C
VDD = +15V
CL = 2500pF
VDD = +15V
50
40
30
20
10
0
1
10
100
1K
15V
10V
VDD = 18V
5V
TA = +25
C
CL = 2500 pF
SUPPLY CURRENT (mA)
FREQUENCY (kHz)
Supply Current vs. Frequency
4
2
0
4
8
12
16
20
Supply Current vs. Supply Voltage
SUPPLY CURRENT (mA)
SUPPLY VOLTAGE (V)
4
3
2
75
25
50
100
150
Supply Current vs. Temperature
SUPPLY CURRENT (mA)
TEMPERATURE (
C)
50
0
25
75
125
TA = +25
C
RL =
INPUT LOGIC "1"
VDD = +18
C
RL =
INPUT LOGIC "1"
150
HYSTERESIS
310mV
200mV
300mV
20
15
10
5
0
1.25
0.25 0.50 0.75
1
1.50 1.75
2
TA = +25
C
OUTPUT VOLTAGE (V)
INPUT VOLTAGE (V)
Voltage Transfer Characteristics
OUTPUT VOLTAGE (mV)
400
300
200
100
CURRENT SOURCED (mA)
0
20
40
60
80
100
VDD = 5V
10V
15V
18V
TA = +25
C
High Output Voltage vs. Current
OUTPUT VOLTAGE (mV)
400
300
200
100
CURRENT SUNK (mA)
0
20
40
60
80
100
VDD = 5V
10V
15V
18V
TA = +25
C
Low Output Voltage vs. Current
4-181
TELCOM SEMICONDUCTOR, INC.
7
6
5
4
3
1
2
8
TC429
1
F
0.1
F
0.1
F
0V
18V
2.4V
0V
2500pF
1
8
6,7
5
4
2
TEK CURRENT
PROBE 6302
+18V
Figure 3. Peak Output Current Test Circuit
TC429
6A SINGLE HIGH-SPEED,
CMOS POWER MOSFET DRIVER
PDF 
ZIP