1
dc2537af
DEMO MANUAL DC2537A
DESCRIPTION
LTC7000
Fast High Voltage Protected
High Side NMOS Static Switch Driver
Demonstration circuit 2537A is a 135V protected, high
side switch featuring the
LTC
®
7000
. The demo board is
designed to switch a 5.5A output load from input voltages
from 8V to 135V. The wide input range and low shut-
down current (1µA typical) make it suitable for automo-
tive, industrial, medical instrument and telecom applica-
tions. This board offers a low 50ns (typical) propagation
delay, fast switching times (<10ns) and 100% duty cycle
operation.
The LTC7000 is a fast high voltage protected high side
N-channel MOSFET driver. An internal charge pump fully
enhances an external N-channel MOSFET switch, allowing
it to remain on indefinitely. Its powerful gate driver can
drive large gate capacitance MOSFETs with very short
transition times, ideal for both high frequency switch-
ing and static switch applications. The LTC7000 operates
over a 3.5V to 135V input supply range. When an external
current sense resistor and internal comparator sense that
the switch current has exceeded a preset level, a fault flag
is asserted and the switch is turned off after a period of
time set by an external timing capacitor. After a cooldown
period, the LTC7000 can be configured to automatically
retry or remain off until input is cycled.
L
, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Analog
Devices, Inc. All other trademarks are the property of their respective owners.
PERFORMANCE SUMMARY
The demo board includes input capacitors and output
diode to accommodate input and output supply induc-
tance when switching loads. The switch can be controlled
directly with external signal or using the on-board on/off
switch. A single-shot pulse generator is included for evalu-
ating switching times while limiting output power. Optional
auxiliary V
CC
input accommodates gate power associated
with high frequency switching. Positions for RC delay net-
work to control inrush current are also included.
The LTC7000 data sheet gives a complete description of
the part, operation and application information. The data
sheet must be read in conjunction with this demo manual
for demo circuit 2537A. Proper board layout is essential
for maximum thermal and electrical performance. See the
data sheet sections for details. The LTC7000 is available
in 16-lead MSOP package and three operating junction
temperature grades (extended and industrial –40°C to
125°C, high temp automotive –40°C to 150°C and a mili-
tary grade –55°C to 150°C.
Design files for this circuit board are available at
http://www.linear.com/demo/DC2537A
Specifications are at T
A
= 25°C
SYMBOL PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
V
IN
Input Voltage
135
V
I
OUT
Output Current
5.5
A
Insertion Drop
V
IN
– V
OUT
, 5.5A Load, Input to Output Terminals
150
mV
V
IN
Start-Up Voltage
V
INP
= 4V
100kΩ Load
8.0
7.0
V
V
V
CCUV
V
CC
Undervoltage Lockout
V
CC
Rising
V
CC
Falling
Hysteresis
6.5
5.8
7.0
6.4
0.6
7.5
6.9
V
V
V
Overcurrent to V
OUT
Low
Turn-On into a 10A Resistive Load
19
µs
Input to Output Propagation Delay
V
IN
= 135V, 50Ω Load, INP = 2.2V to V
OUT
= 13.5V
50
ns
Output Rise Time
V
IN
= 135V, 50Ω Load, 10% to 90%
6.5
ns
