1
dc1886bfa
DEMO MANUAL DC1886B
DESCRIPTION
LTC4232 and LTC4232-1:
5A Integrated
Hot Swap Controller
Demonstration circuit 1886B features the
5A integrated Hot Swap™ controllers. The
LTC4232 is ideally suited for demanding power distribution
control in 2.9V to 15V applications for hot board inser-
tion protection, high side power switching, and electronic
circuit breaker functions. The LTC4232 provides a rich set
of features to support Hot Swap applications including:
• 2% accurate undervoltage and overvoltage comparators
• Thermal protection
• Adjustable inrush current control
• Adjustable, 10% accurate current limit with program-
mable cutout time
• Foldback current limiting
• Programmable output voltage ramp rate
• Configurable auto-retry or latchoff on overcurrent faults
• Power good and fault outputs
• Debounce time during supply turn-on
PERFORMANCE SUMMARY
The LTC4232 debounce time is 100ms, while the LTC4232-1
is 16ms. Both are available in a 16-lead 5mm × 3mm DFN
package. The LTC4232 is showcased on demonstration
circuit 1886B-A. The LTC4232-1 is installed on DC1886B-B.
Both demo boards are configured for 12V application. By
changing a few passive components, 2.9V to 15V applica-
tions can be easily evaluated.
The LTC4232 has limited output voltage slew rate with
a typical value of 300V/s, while the LTC4232-1 does not
have a special circuit to limit this parameter. The natural
(maximum) gate voltage slew rate (S
N
) of the LTC4232-1
is defined by the internal MOSFET C
RSS
(reverse transfer
capacitance) value and gate driver current capability. It is
48000V/s as a typical value.
Design files for this circuit board are available at
http://www.linear.com/demo/DC1886B
L
, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
Hot Swap is a trademark of Linear Technology Corporation. All other trademarks are the
property of their respective owners.
(T
A
= 25°C)
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
V
DD
Board Input Supply Range
Min Is UV, Max Is OV
9.2
12
15.1
V
dV
GATE
/dt
GATE Pin Turn-On Ramp Rate
LTC4232
LTC4232-1 with 10nF GATE Capacitor
0.15
1.7
0.3
2.4
0.55
3.5
V/ms
V/ms
R
ON
Sense Resistor On-Resistance
15
33
50
mΩ
I
LIM(TH)
Current Limit Threshold
V
FB
= 1.23V, No R
SET
V
FB
= 0V
V
FB
= 1.23V, R
SET
= 20k
5.0
1.2
2.6
5.6
1.5
2.9
6.1
1.8
3.3
A
A
A
V
TH
OV, UV, FB Pin Threshold Voltage
V
IN
Rising
1.21
1.235
1.26
V
V
UV(RTH)
UV Pin Reset Threshold Voltage
V
UV
Falling
0.55
0.62
0.7
V
V
FB(HYST)
FB Pin Power Good Hysteresis
10
20
30
mV
t
D(AUTO-RETRY)
Auto-Retry Turn-On Delay (Internal)
LTC4232
LTC4232-1
50
8
100
16
150
24
ms
ms
T
ADJUST
Timer Period for ADJUSTABLE Option
LTC4232
LTC4232-1
9.5
0.95
12.3
1.23
16.8
1.68
ms
ms
