MAX4795ETT-T Maxim Integrated, MAX4795ETT-T Datasheet - Page 7

• Manufacturer Part Number: MAX4795ETT-T
• Description: Power Switch ICs - Power Distribution
• Manufacturer: Maxim Integrated

Specifications of MAX4795ETT-T

• Number Of Outputs: 1
• Operating Supply Voltage: 2 V to 4.5 V
• Maximum Operating Temperature: + 85 C
• Package / Case: TDFN EP-6
• Minimum Operating Temperature: - 40 C

When the forward or reverse current-limit threshold is
exceeded, t
The timer resets if the overcurrent condition disappears
before t
is started immediately after t
during that time, the switch is latched off and FLAG
asserts. At the end of t
again. If the fault still exists, the cycle is repeated. If the
fault has been removed, the switch stays on and FLAG
deasserts.
The autoretry feature saves system power in the case
of an overcurrent or short-circuit condition. During
t
the current limit. During t
the current through the switch is zero. Instead of
observing the full load current, the switch sees the
equivalent load current times duty cycle or I
I
t
cycle is 6%, which results in a 94% power savings over
the switch being on the entire time. The duty cycle is
consistent across the process and devices.
When the forward or reverse current-limit threshold is
exceeded, t
resets if the overcurrent condition disappears before
t
asserts if the overcurrent condition continues up to the
end of the blanking time. Reset the switch by either tog-
gling ON (Figure 3) or cycling the input voltage.
The MAX4795–MAX4798 feature 14ms (min) fault blank-
ing. Fault blanking allows current-limit faults, including
momentary short-circuit faults that occur when hot
swapping a capacitive load, and also ensures that no
fault is issued during power-up. When a load transient
causes the device to enter current limit, an internal
counter starts. If the load-transient fault persists beyond
the fault-blanking timeout, FLAG asserts low. Load-tran-
sient faults less than t
put assertion. Only current-limit faults are blanked.
A thermal fault causes FLAG to assert immediately and
does not wait for the blanking time.
The MAX4795–MAX4798 have a thermal-shutdown fea-
ture to protect the devices from overheating. The switch
BLANK
BLANK
BLANK
LOAD
, when the switch is on, the supply current is at
✕
BLANK
= 37ms and typical t
has elapsed. The switch is shut off and FLAG
t
BLANK
BLANK
BLANK
has elapsed. A retry time delay, t
Autoretry (MAX4796/MAX4798)
Latchoff (MAX4795/MAX4797)
/(t
_______________________________________________________________________________________
BLANK
timer begins counting (Figure 2).
timer begins counting. The timer
BLANK
450mA/500mA Current-Limit Switches
RETRY
RETRY
+ t
do not cause a FLAG out-
RETRY
, the switch is turned on
BLANK
RETRY
Thermal Shutdown
, when the switch is off,
= 555ms, the duty
Fault Blanking
). With a typical
has elapsed and
SUPPLY
RETRY
=
,
turns off and FLAG goes low immediately (no fault
blanking) when the junction temperature exceeds
+150°C. The switches with autoretry turn back on when
the device temperature drops approximately 15°C. The
switches with latchoff require ON cycling.
To limit the input voltage drop during momentary output
short-circuit conditions, connect a capacitor from IN to
GND. A 0.1µF ceramic capacitor is adequate for most
applications; however, higher capacitor values further
reduce the voltage drop at the input and are recom-
mended for lower voltage applications.
Figure 3. MAX4795/MAX4797 Latch-Off Fault Blanking
CURRENT
FLAG PIN
FLAG PIN
VOLTAGE
CURRENT
VOLTAGE
SWITCH
STATUS
STATUS
STATUS
SWITCH
STATUS
ON PIN
IN PIN
LOAD
LOAD
OFF
OFF
ON
ON
Applications Information
t
BLANK
t
BLANK
t
(a)
BLANK
t
BLANK
Input Capacitor
7