MAX5925DEUB+ Maxim Integrated Products, MAX5925DEUB+ Datasheet - Page 17

• Manufacturer Part Number: MAX5925DEUB+
• Description: IC HOT-SWAP CTRLR N-CH 10-UMAX
• Manufacturer: Maxim Integrated Products
• Type: Hot-Swap Controllerr

Specifications of MAX5925DEUB+

• Applications: General Purpose
• Internal Switch(s): No
• Voltage - Supply: 1 V ~ 13.2 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 10-MSOP, Micro10™, 10-uMAX, 10-uSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

In applications where the external MOSFET’s on-resis-
tance is used as a sense resistor to determine overcur-
rent conditions, a 3300ppm/°C temperature coefficient
is desirable to compensate for the R
ture coefficient. Use the MAX5926’s TC input to select
the circuit-breaker programming current’s temperature
coefficient, TC
ature coefficient is preset to 0ppm/°C, and the
MAX5925’s is preset to 3300ppm/°C.
Setting TC
threshold to track and compensate for the increase in the
MOSFET’s R
MOSFETs have a temperature coefficient within a
3000ppm/°C to 7000ppm/°C range. Refer to the MOSFET
data sheet for a device-specific temperature coefficent.
R
therefore be expressed as functions of temperature. At
a given temperature, the MAX5925/MAX5926 indicate
an overcurrent condition when:
where V
graphically portrays operating conditions for a MOSFET
with a 4500ppm/°C temperature coefficient.
Most circuit component values may be calculated with
the aid of the MAX5924–MAX5926. The "Design calcula-
tor for choosing component values" software can be
downloaded from the MAX5924–MAX5926 Quickview on
the Maxim website.
Select the external n-channel MOSFET according to the
application’s current and voltage level. Table 3 lists some
recommended components. Choose the MOSFET’s
on-resistance, R
voltage drop at full load to limit the MOSFET power dis-
sipation. High R
loss and output ripple if the board has pulsing loads or
triggers an external undervoltage reset monitor at full
load. Determine the device power-rating requirement to
accommodate a short circuit on the board at startup
with the device configured in autoretry mode .
Using the MAX5924/MAX5925/MAX5926 in latched mode
allows the consideration of MOSFETs with higher R
and lower power ratings. A MOSFET can typically with-
DS(ON)
I
Circuit-Breaker Temperature Coefficient
TRIPSLOW
1V to 13.2V, n-Channel Hot-Swap Controllers
CB,OS
and I
ICB
DS(ON)
x R
CB
ICB
to 3300ppm/°C allows the circuit-breaker
is the worst-case offset voltage. Figure 14
Applications Information
DS(ON)
DS(ON)
DS(ON)
are temperature dependent, and can
______________________________________________________________________________________
(see Table 2). The MAX5924 temper-
with increasing temperature. Most
, low enough to have a minimum
(T) ≥ I
can cause undesired power
Component Selection
CB
(T) x R
n-Channel MOSFET
DS(ON)
CB
+
|
V
CB,OS
tempera-
DS(ON)
Require No Sense Resistor
|
stand single-shot pulses with higher dissipation than the
specified package rating. Low MOSFET gate capaci-
tance is not necessary since the inrush current limiting is
achieved by limiting the gate dv/dt. Table 4 lists some
recommended manufacturers and components.
Be sure to select a MOSFET with an appropriate gate
drive (see the Typical Operating Characteristics ).
Typically, for V
MOSFET.
Table 2. Programming the Temperature
Coefficient (MAX5926)
Table 3. Suggested External MOSFETs
Figure 14. Circuit-Breaker Trip Point and Current-Sense
Voltage vs. Temperature
APPLICATION
CURRENT (A)
10
1
2
5
50
45
40
35
30
25
20
High
Low
TC
-40
International Rectifier
IRF7401
Siliconix Si4378DY
Siliconix SUD40N02-06
Siliconix SUB85N02-03
V
R
CC
S
DS(ON)
= V
CIRCUIT-BREAKER TRIP REGION
-15
CC
less than 3V, select a 2.5V V
(25) = 6.5mΩ
V
(3300ppm/°C)
= 13.2V, R
CB
(V
= I
TEMPERATURE (°C)
10
PART
V
(4500ppm/°C)
SENSE
CB
SENSE
(T) x R
CB
≥ V
35
= R
= 672Ω, I
CB
CB
DS(ON)
)
+ V
60
CB,OS
(T) x I
TRIPSLOW
TC
ICB
LOAD(MAX)
85
SO-8
SO-8
DPAK
D2PAK
3300
DESCRIPTION
= 5A,
(ppm/°C)
0
110
GS
17