MAX5923EUP+ Maxim Integrated Products, MAX5923EUP+ Datasheet - Page 10

• Manufacturer Part Number: MAX5923EUP+
• Description: IC HOT-SWAP SWITCH +60V 20-TSSOP
• Manufacturer: Maxim Integrated Products
• Series: Simple Swapper™r
• Type: Hot-Swap Switchr

Specifications of MAX5923EUP+

• Applications: General Purpose
• Internal Switch(s): Yes
• Current Limit: 800mA
• Voltage - Supply: 16 V ~ 60 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 20-TSSOP
• Product: Controllers & Switches
• Supply Voltage (max): 60 V
• Supply Voltage (min): 16 V
• Power Dissipation: 879 mW
• Operating Temperature Range: - 40 C to + 85 C
• Mounting Style: SMD/SMT
• Supply Current: 1 mA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

+60V Simple Swapper Hot-Swap Switch
Figure 3. Periodic Overcurrent Without Generating a Fault
During an output short-circuit condition, the energy stored
in the output capacitor is dumped onto the short and
builds up a large current in the power path and its para-
sitic inductance. The larger the output capacitor, the larg-
er the current buildup. The parasitic inductive current
circulates through the short circuit and brings OUT below
ground level. A Schottky diode is needed at the output to
provide the path for this circulating current and to prevent
OUT from going too far below ground and exceeding the
MAX5923’s absolute maximum ratings.
For an output capacitor with low ESR (ceramic and film
type), and with values of 0.47µF or less, a B1100LB
(100V, 1A Schottky) is required as shown in the Typical
Application Circuit. For higher values of capacitance,
more robust clamping is required. For applications using
aluminum electrolytic capacitors, which have relatively
high ESR, the requirement of the clamp diode is reduced.
Good layout with less parasitic trace inductance also
helps in reducing the clamping diode requirement and
should be examined on a case-by-case basis.
POK goes open-drain t
rises to within 0.75V (V
t
10
POK_LOW
V
I
FAULT
LIMIT
I
OUT
______________________________________________________________________________________
0V
0V
Output Clamping During Short Circuit
(1.4ms) after V
t
OC
t
RESTART
THPOK
POK_HIGH
OUT
) from V
drops 0.75V below V
Power-OK (POK)
t
(88ms) after V
<
t
OC
IN
. POK goes low
IN
OUT
t
.
Zero-current detection is enabled if ZC_EN is high and
only after the startup period has finished (indicated by
POK going high). When V
current threshold (V
350ms, a zero-current fault is generated. The MOSFET
is turned off and ZC is latched low. ZC is open drain
during initial power-up. After a zero-current fault has
occurred, the MAX5923 is latched off and is restarted
by applying a low-to-high transition on the EN pin.
At any time during a zero-current condition, if V
goes above V
(t
zero and a zero-current fault is not generated. Bring
ZC_EN low to disable the zero-current detection func-
tion. ZC stays high impedance in this mode.
If the MAX5923 die temperature reaches +150°C, an
overtemperature fault is generated. The MOSFET turns
off and FAULT goes low. The MAX5923 die tempera-
ture must cool down below +120°C before the overtem-
perature fault condition is removed (see the Fault
Management section).
FAULT goes low when there is an overcurrent fault and/or
an overtemperature fault. FAULT is open drain otherwise.
After a fault, the FAULT signal is latched low. FAULT is
unlatched at the beginning of the next power mode.
The MAX5923 offers either latched-off or autoretry fault
management configurable by the LATCH input.
Bringing LATCH high puts the device into latch mode
while pulling LATCH low selects the autoretry option.
In latch mode, the MAX5923 turns the MOSFET off and
keeps it off after an overcurrent fault or an overtemper-
ature fault. After the fault condition goes away, recycle
the power supplies or toggle the EN pin low and high
again to unlatch the part. However, the part waits a
t
condition and resuming normal operation.
In autoretry mode, MAX5923 turns the MOSFET off after
an overcurrent or overtemperature fault. After the fault
condition is removed, the device waits a t
(1.92s) and then automatically restarts. If the fault was
due to an overtemperature condition, the MAX5923 waits
for its die temperature to cool down below the hysteresis
level before starting the t
RESTART
ZC_DEG
period (1.92s) before recovering from a fault
= 10ms), the zero-current counter resets to
ZCTH
for the zero-current deglitch time
ZCTH
RESTART
Zero-Current Detection
) for a continuous t
SENSE
Fault Report ( FAULT )
Thermal Shutdown
Fault Management
time.
falls below the zero-
RESTART
ZCDEL
period
SENSE
=