TC427CPA Microchip Technology, TC427CPA Datasheet - Page 6

• Manufacturer Part Number: TC427CPA
• Description: IC MOSFET DVR 1.5A DUAL HS 8-DIP
• Manufacturer: Microchip Technology
• Type: Microcontrollerr

Specifications of TC427CPA

• Number Of Outputs: 2
• Package / Case: 8-DIP (0.300", 7.62mm)
• Configuration: Low-Side
• Input Type: Non-Inverting
• Delay Time: 50ns
• Current - Peak: 1.5A
• Number Of Configurations: 2
• Voltage - Supply: 4.5 V ~ 18 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Through Hole
• Rise Time: 30 ns
• Fall Time: 30 ns
• Supply Voltage (min): 4.5 V
• Supply Current: 8 mA
• Maximum Power Dissipation: 730 mW
• Maximum Operating Temperature: + 70 C
• Mounting Style: Through Hole
• Minimum Operating Temperature: 0 C
• Number Of Drivers: 2
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• High Side Voltage - Max (bootstrap): -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 158-1055; 158-1055

TC426/TC427/TC428
3.0
3.1
Charging and discharging large capacitive loads
quickly requires large currents. For example, charging
a 1000 pF load to 18V in 25 nsec requires an 0.72A
current from the device power supply.
To ensure low supply impedance over a wide frequency
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 μF film capacitor in parallel with one or two
0.1 μF ceramic disk capacitors normally provides
adequate bypassing.
3.2
The TC426 and TC428 contain inverting drivers.
Ground potential drops developed in common ground
impedances from input to output will appear as
negative feedback and degrade switching speed
characteristics.
Individual ground returns for the input and output
circuits or a ground plane should be used.
3.3
The input voltage level changes the no-load or
quiescent supply current. The N-channel MOSFET
input stage transistor drives a 2.5 mA current source
load. With a logic ‘1’ input, the maximum quiescent
supply current is 8 mA. Logic ‘0’ input level signals
reduce quiescent current to 0.4 mA maximum.
Minimum power dissipation occurs for logic ‘0’ inputs
for the TC426/TC427/TC428. Unused driver inputs
must be connected to V
The drivers are designed with 100 mV of hysteresis.
This provides clean transitions and minimizes output
stage current spiking when changing states. Input
voltage thresholds are approximately 1.5V, making the
device TTL compatible over the 4.5V to 18V supply
operating range. Input current is less than 1 μA over
this range.
The TC426/TC427/TC428 may be directly driven by
the TL494, SG1526/1527, SG1524, SE5560, and
similar switch-mode power supply integrated circuits.
DS21415C-page 6
APPLICATIONS INFORMATION
Supply Bypassing
Grounding
Input Stage
DD
or GND.
3.4
The supply current vs frequency and supply current
vs capacitive load characteristic curves will aid in
determining power dissipation calculations.
The TC426/TC427/TC428 CMOS drivers have greatly
reduced quiescent DC power consumption. Maximum
quiescent current is 8 mA compared to the DS0026 40
mA specification. For a 15V supply, power dissipation
is typically 40 mW.
Two other power dissipation components are:
• Output stage AC and DC load power.
• Transition state power.
Output stage power is:
Where:
In power MOSFET drive applications the P
negligible. MOSFET power transistors are high-imped-
ance, capacitive input devices. In applications where
resistive loads or relays are driven, the P
will normally dominate.
The magnitude of P
cases:
During output level state changes, a current surge will
flow through the series connected N and P channel
output MOSFETS as one device is turning “ON” while
the other is turning “OFF”. The current spike flows only
during output transitions. The input levels should not be
maintained between the logic ‘0’ and logic ‘1’ levels.
Unused driver inputs must be tied to ground and
not be allowed to float. Average power dissipation will
be reduced by minimizing input rise times. As shown in
the characteristic curves, average supply current is
frequency dependent.
A.
Po = P
Vo = DC output voltage
I
f
Vs = Supply voltage
DC
1. f
2. C
3. Vs = 18V
4. P
= Vo (I
= DC output load current
= Switching frequency
Power Dissipation
AC
L
DC
= 200 kHZ
=1000 pf
= 65 mW
DC
+ PAC
) + f C
AC
is readily estimated for several
© 2006 Microchip Technology Inc.
L
V
S
2
B.
1. f
2. C
3. Vs = 15V
4. P
AC
L
= 200 kHz
=1000 pf
= 45 mW
DC
component
DC
term is