MAX869L Maxim, MAX869L Datasheet - Page 6

• Manufacturer Part Number: MAX869L
• Description: The MAX869L P-channel load switch features an accurate user-set current limit and low on-resistance
• Manufacturer: Maxim

2A, Current-Limited, High-Side
P-Channel Switch with Thermal Shutdown
_____________________Pin Description
6
(T
12, 13, 16
11, 14, 15
____________________________Typical Operating Characteristics (continued)
1, 4, 5,
2, 3, 6,
A
_______________________________________________________________________________________
PIN
= +25°C, unless otherwise noted.)
10
7
8
9
A
B
C
D
0V
0V
0A
0V
V
A: V
B: V
*REFER TO TYPICAL OPERATING CIRCUIT
IN
= 5V, I
ON
OUT
, 5V/div
NAME
FAULT
, 2V/div
GND
OUT
SET
ON
OUT
IN
USB* CIRCUIT OUTPUT RISE TIME
= 1A, C
IN
Input, P-channel MOSFET source.
Bypass IN with a 1µF capacitor to
ground.
Switch output. P-channel MOSFET
drain. Bypass OUT with a 0.1µF
capacitor to GND.
Active-Low Switch-On Input. A logic
low turns the switch on.
Ground
Set Current-Limit Input. A resistor
from SET to ground sets the current
limit for the switch. R
I
rent limit in amperes.
Fault-Indicator Output. This open-
drain output goes low when in cur-
rent limit or when the die temperature
exceeds +135°C. FAULT remains low
for Turn-On Time + 50µs during start-
up.
LIMIT
= 1µF, C
500µs/div
C: I
D: V
, where I
OUT
OUT
FAULT
= 120µF
, 0.5A/div
, 2V/div
FUNCTION
LIMIT
is the desired cur-
SET
= 1,184 /
The MAX869L P-channel MOSFET power switch limits
output current to a programmed level. When the output
current passes through the main switch, a smaller cur-
rent also passes through the replica switch (I
and through R
exceeds the trip voltage of 1.24V, the current-limit error
amplifier regulates the output current to the pro-
grammed current limit, I
This switch is not bidirectional; therefore, the input volt-
age must be higher than the output voltage.
The MAX869L features internal current-limiting circuitry
with a maximum programmable value (I
For best performance, set the current limit (I
between 0.2 I
remains in effect throughout the input supply-voltage
range.
Program the current limit with a resistor (R
SET to ground (Figure 2) as follows:
where I
_______________Detailed Description
A
B
C
D
LIMIT
0V
0V
0A
0V
V
A: V
B: V
IN
= 5V, I
ON
OUT
I
R
SET
is the desired current limit.
, 5V/div
SET
, 2V/div
SET
MAX
OUT
USB* CIRCUIT OUTPUT FALL TIME
= I
= 1.24V / I
= 1A, C
(Figure 1). When the voltage on R
LIMIT
≤ I
IN
LIMIT
Setting the Current Limit
= 1µF, C
LIMIT
/ 955
500µs/div
C: I
D: V
SET
OUT
OUT
≤ I
(400mA to 2.4A).
FAULT
, 0.5A/div
= 120µF
MAX
= 1,184 / I
, 2V/div
. This current limit
MAX
LIMIT
OUT
SET
) of 2.4A.
) from
LIMIT
/ 955)
SET
)