MAX5901LAETT-T Datasheet, PDF (5/14 Pages) Maxim Integrated Products – -100V, SOT23/TDFN, Simple Swapper Hot-Swap Controllers

-100V, SOT23/TDFN, Simple Swapper
Hot-Swap Controllers
PIN
MAX5900
MAX5901
1
1
2
2
3
3
4
4
5
—
—
5
6
6
—
—
Pin Description
NAME
V_EE
DRAIN
GATE
GND
PGOOD
PGOOD
ON/OFF
EP
FUNCTION
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 (see the
Layout Guidelines section).
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_EE.
Power-Good Output. PGOOD is an n-channel, open-drain, active-high output,
referenced to V_EE.
ON/OFF Control Input. ON/OFF is referenced to V_EE. 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. See the Under-
voltage Lockout section in the Applications Information. Internally clamped to
nominally 3V through a 1kΩ resistor (see Figure 1).
Exposed Pad (TDFN only). Connect to V_EE.
Detailed Description
The MAX5900/MAX5901 are integrated hot-swap con-
troller ICs contained in 6-pin SOT23/TDFN packages.
They allow a board to be safely hot plugged into a live
backplane without causing a glitch on the power-sup-
ply rail. They are well suited for -48V telecom power
systems, allowing a cost-effective, simple, and com-
pact 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 MOS-
FET 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 undervolt-
age 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,
GND
828kΩ*
MAX5900
MAX5901
ON/OFF
V_EE
1kΩ*
34.5kΩ*
3V
CONTROL
LOGIC
PGOOD
(PGOOD)
N
V_EE
V_EE
466kΩ*
GATE DRAIN
( ) ARE FOR THE MAX5901 ONLY.
*RELATIVE TOLERANCE ±1%, ABSOLUTE TOLERANCE ±20% TYPICAL.
Figure 1. Functional Diagram
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