MAX5933BESA+ Maxim Integrated Products, MAX5933BESA+ Datasheet - Page 9

• Manufacturer Part Number: MAX5933BESA+
• Description: IC HOT-SWAP CONTROLLER 8-SOIC
• Manufacturer: Maxim Integrated Products
• Type: Hot-Swap Controllerr

Specifications of MAX5933BESA+

• Applications: General Purpose
• Internal Switch(s): No
• Voltage - Supply: 33 V ~ 80 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (0.154", 3.90mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The MAX5933_ and MAX5947_ are fully integrated hot-
swap controllers for positive supply rails. The devices
allow for the safe insertion and removal of circuit cards
into live backplanes without causing glitches on the
backplane power-supply rail. During startup, the
MAX5933_ and MAX5947_ act as current regulators
using an external sense resistor and a MOSFET to limit
the amount of current drawn by the load.
The MAX5933_ operate from a +33V to +80V supply
voltage range and have a default undervoltage lockout
(UVLO) set to +31V. The MAX5947_ operate from a
+9V to +80V supply voltage range and have a default
UVLO set to +8.3V. The UVLO threshold is adjustable
using a resistive divider connected from V
GND (see Figure 5).
Figure 5. Application Circuit
Positive High-Voltage, Hot-Swap Controllers
24V
V
GND
IN
_______________________________________________________________________________________
Detailed Description
49.9kΩ
0.68µF
3.4kΩ
1%
1%
C2
R1
R2
0.1µF
1
5
ON
TIMER
V
CC
8
CC
0.025Ω
R
SENSE
MAX5933A
to ON to
GND
SENSE
4
7
10Ω
5%
R5
IRF530
GATE
Q1
6
The MAX5933_ and MAX5947_ monitor the input volt-
age, the output voltage, the output current, and the die
temperature. These devices feature power-good outputs
(PWRGD/PWRGD) to indicate the status of the output
voltage by monitoring the voltage at FB (see the Power-
Good Detection section).
As shown in Figure 5, a sense resistor is connected
between V
across the sense resistor (V
the voltage at FB ≥ 0.5V. The current-limit threshold
(V
FB decreases from 0.5V to 0V.
An undervoltage fault is detected when ON goes below
the threshold (V
goes low as a result to turn off the MOSFET. ON must
pass the V
MOSFET again.
PWRGD
SENSETRIP
FB
2
3
D1
CMPZ5248B
1kΩ
5%
R6
10nF
C1
CC
ONH
) decreases linearly from 47mV to 12mV as
ONL
and SENSE to regulate the voltage
= 1.313V threshold to turn on the
R3
59kΩ
1%
R4
3.57kΩ
1%
= 1.233V) and the voltage at GATE
R7
24kΩ
5%
IN
- V
C
L
SENSE
PWRGD
) to 47mV when
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