TC642_13 Datasheet, PDF (14/28 Pages) Microchip Technology – PWM Fan Speed Controller with FanSense™ Technology

TC642
TABLE 5-2: TRANSISTORS AND MOSFETS FOR Q₁ (V_DD = 5V)
Device
Package
Max. V_BE(sat)/V_GS
(V)
Min. H_FE
V_CEO/V_DS
(V)
Fan Current
(mA)
Suggested
R_BASE ()
MMBT2222A
SOT-23
1.2
50
40
150
800
MPS2222A
TO-92
1.2
50
40
150
800
MPS6602
TO-92
1.2
50
40
500
301
SI2302
SOT-23
2.5
NA
20
500
Note 1
MGSF1N02E
SOT-23
2.5
NA
20
500
Note 1
SI4410
SO-8
4.5
NA
30
1000
Note 1
SI2308
SOT-23
4.5
NA
60
500
Note 1
Note 1: A series gate resistor may be used in order to control the MOSFET turn-on and turn-off times.
5.6 Latch-up Considerations
As with any CMOS IC, the potential exists for latch-up
if signals are applied to the device which are outside
the power supply range. This is of particular concern
during power-up if the external circuitry (such as the
sensor network, V_MIN divider or shutdown circuit) is
powered by a supply different from that of the TC642.
Care should be taken to ensure that the TC642’s V_DD
supply powers up first. If possible, the networks
attached to V_IN and V_MIN should connect to the V_DD
supply at the same physical location as the IC itself.
Even if the IC and any external networks are powered
by the same supply, physical separation of the
connecting points can result in enough parasitic
capacitance and/or inductance in the power supply
connections to delay one power supply “routing” versus
another.
DS21444D-page 14
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