MAX5900 Maxim, MAX5900 Datasheet - Page 5

• Manufacturer Part Number: MAX5900
• Description: -100V SOT23 Simple Swapper Hot-Swap Controllers
• Manufacturer: Maxim

The MAX5900/MAX5901 are integrated hot-swap con-
troller ICs contained in 6-pin SOT23 packages. They
allow a board to be safely hot plugged into a live back-
plane without causing a glitch on the power-supply rail.
They are well suited for -48V telecom power systems,
allowing a cost-effective, simple, and compact design.
The MAX5900/MAX5901 operate from -9V to -100V to
cover the standard telecom voltage range, and to serve
more generalized applications. These devices require
only an external N-channel power MOSFET to provide
hot-swap control. Figure 1 shows a functional diagram
of the MAX5900/MAX5901.
The MAX5900/MAX5901 control an external N-channel
power MOSFET placed in the negative power-supply
pathway. When power is first applied, the MAX5900/
MAX5901 keep the MOSFET turned off. The
MAX5900/MAX5901 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
300ms (typ), the MAX5900/MAX5901 begin to gradually
turn on the MOSFET. During this turn-on phase, the
MAX5900/MAX5901 slowly enhance the MOSFET,
allowing the voltage on the load, i.e. the drain of the
MOSFET, to fall no faster than 10V/ms (typ). The inrush
MAX5900
—
1
2
3
4
5
6
PIN
MAX5901
_______________________________________________________________________________________
-100V SOT23 Simple Swapper Hot-Swap
—
1
2
3
4
5
6
Detailed Description
PGOOD
PGOOD
ON/OFF
DRAIN
NAME
GATE
GND
V
EE
Negative Supply Voltage Input and External N-Channel MOSFET Source
Connection
Drain Sense Input for External N-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 MAX5900/MAX5901 and the MOSFET (aee Layout
Guidelines).
Gate Drive Output for External N-Channel MOSFET
Ground Connection.
Power-Good Output. PGOOD is an N-channel, open-drain, active-low output,
referenced to V
Power-Good Output. PGOOD is an N-channel, open-drain, active-high output,
referenced to V
ON/OFF Control Input. ON/OFF is referenced to V
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. See Under-
voltage Lockout in the Applications Information section of this datasheet.
Internally clampted to nominally 3V through a 1kΩ resistor (see Figure 1).
EE
EE
.
.
Figure 1. Functional Diagram
ON/OFF
GND
V
EE
( ) ARE FOR THE MAX5901 ONLY.
* RELATIVE TOLERANCE ±1%, ABSOLUTE TOLERANCE ±20% TYPICAL.
828kΩ*
34.5kΩ*
V
EE
FUNCTION
1kΩ*
3V
GATE
CONTROL
MAX5900
MAX5901
LOGIC
EE
Controllers
. Drive ON/OFF above 1.38V
DRAIN
Pin Description
466kΩ*
V
EE
N
PGOOD
(PGOOD)
5