MAX5903LCEUT+T Maxim Integrated Products, MAX5903LCEUT+T Datasheet - Page 5

• Manufacturer Part Number: MAX5903LCEUT+T
• Description: IC HOT-SWAP CONTROLLER SOT23-6
• Manufacturer: Maxim Integrated Products
• Series: Simple Swapper™r
• Type: Hot-Swap Controllerr

Specifications of MAX5903LCEUT+T

• Applications: General Purpose
• Internal Switch(s): No
• Voltage - Supply: 9 V ~ 72 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: SOT-23-6
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The MAX5902/MAX5903 are integrated hot-swap con-
troller ICs contained in 6-pin SOT23 and TDFN pack-
ages. They allow a board to be safely hot-plugged into
a live backplane without causing a glitch on the power-
supply rail. They are well suited for +48V power sys-
tems allowing cost-effective, simple, and compact
design. The MAX5902/MAX5903 operate from +9V to
+72V to cover a wide range of end equipment hot-swap
needs. They require only an external p-channel power
MOSFET to provide hot-swap control. Figure 1 shows a
functional block diagram of the MAX5902/MAX5903.
The MAX5902/MAX5903 controls an external p-channel
power MOSFET placed in the positive power-supply
pathway. When power is first applied, the MAX5902/
MAX5903 keep the MOSFET turned off. The
MAX5902/MAX5903 hold the MOSFET off indefinitely if
ON/OFF is held low, if the supply voltage is below the
undervoltage lockout level, or if the die temperature
exceeds +125°C. If none of these conditions exist for
150ms (typ), the MAX5902/MAX5903 begin to gradually
turn on the MOSFET. During this turn-on phase, the
MAX5902/MAX5903 slowly enhance the MOSFET,
allowing the voltage on the load, i.e. the drain of the
MOSFET, to rise at a rate of 9V/ms (typ). The inrush cur-
rent to the load is thus limited to a level proportional to
the load capacitance, and the constant slew rate. After
MAX5902
+72V, SOT23/TDFN, Simple Swapper Hot-Swap
—
—
1
2
3
4
5
6
PIN
MAX5903
—
—
1
2
3
4
5
6
_______________________________________________________________________________________
Detailed Description
PGOOD
PGOOD
ON/OFF
DRAIN
NAME
GATE
GND
EP
V
S
Positive Supply Voltage Input and External p-Channel MOSFET Source Connection
Drain Sense Input for External p-Channel MOSFET. Connect DRAIN as close as
possible to the MOSFET’s drain and use wide circuit traces to assure good thermal
coupling between the MAX5902/MAX5903 and the MOSFET. See Layout Guidelines
Section.
Gate Drive Output for External p-Channel MOSFET
Ground Connection
Power-Good Output. PGOOD is an n-channel, open-drain, active-low output,
referenced to GND.
Power-Good Output. PGOOD is an n-channel, open-drain, active-high output,
referenced to GND.
ON/OFF Control Input. ON/OFF is referenced to GND. Drive ON/OFF above 1.38V or
leave unconnected to enable the device. Drive ON/OFF below 1V to disable the device.
ON/OFF is also used to adjust the UVLO threshold. Internally clamped to nominally 3V
through a 1kΩ resistor (See Figure 1). (See the Undervoltage Lockout section in the
Applications Information.)
Exposed Pad (TDFN only). Connect to GND.
the MOSFET is fully enhanced, and the load voltage is
settled to its final value, the MAX5902A/ MAX5903A and
MAX5902L/MAX5903L monitor the voltage drop across
the MOSFET. If the voltage drop exceeds the circuit-
breaker threshold the MAX5902A/MAX5903A and
Figure 1. Functional Block Diagram
ON/OFF
GND
V
S
( ) ARE FOR THE MAX5903 ONLY
* RELATIVE TOLERANCE ±1%, ABSOLUTE TOLERANCE ±50% (TYP)
FUNCTION
*
828kΩ
*
34.5kΩ
GND
1kΩ
3V
*900kΩ
*650kΩ
MAX5902
MAX5903
DRAIN
Controllers
CONTROL
LOGIC
Pin Description
GATE
GND
PGOOD
(PGOOD)
5