MAX16910 Datasheet, PDF (12/13 Pages) Maxim Integrated Products – 200mA, Automotive, Ultra-Low Quiescent Current, Linear Regulator

200mA, Automotive, Ultra-Low
Quiescent Current, Linear Regulator
After determining the allowable power dissipation, cal-
culate the maximum allowable output current, without
exceeding the +150°C junction temperature, using the
following formula:
I _OUT(MAX)
=
P_D
V_IN − V_OUT
The above equations do not include the negligible power
dissipation from self-heating due to the device ground
current.
Example 1 (TDFN-EP Package):
TA = +125°C, VIN = 16V, VOUT = 3.3V
Calculate the maximum allowable power dissipation at
the given temperature as follows:
P_D
=
1.951W
−
0.0244 ^W
°C
×
(125°C
−
70°C)
=
609mW
And establish the maximum output current:
I _OUT(MAX)
= ^609mW ≅ 48mA
16V − 3.3V
Selecting Timeout Capacitor
The reset timeout period is adjustable to accommodate
a variety of microprocessor applications. Adjust the
reset timeout period by connecting a capacitor between
TIMEOUT and GND.
t_RP =
1.25 × C _TIMEOUT
I_TO
where tRP is in ms and CTIMEOUT is in nF.
Leave TIMEOUT unconnected to select the internally
fixed timeout period. CTIMEOUT must be a low-leakage
(< 10nA) type capacitor. Ceramic capacitors are recom-
mended; do not use capacitor values lower than 100pF
to avoid the influence of parasitic capacitances.
Exposed Pad
The MAX16910 package features an exposed thermal
pad on its underside that should be used as a heatsink.
This pad lowers the package’s thermal resistance by
providing a direct heat-conduction path from the die
to the PCB. Connect the exposed pad and GND to the
system ground using a large pad or ground plane, or
multiple vias to the ground plane layer.
Example 2 (TDFN-EP Package):
TA = +50°C, VIN = 9V, VOUT = 5V
Calculate the maximum allowable power dissipation at
the given temperature as follows:
PD = 1.951W
Find the maximum output current:
I _OUT(MAX)
=
1.951W
9V − 5V
=
488mA ⇒
I _OUT(MAX)
=
I_SC = 330mA (typ)
In Example 2, the maximum output current is calculated
as 488mA. The allowable output current cannot exceed
the given internal current limit for the device of 330mA
(typ).
2.4
1.951W
2.2 _{8-PIN TDFN-EP}
2.0
1.8
1.861W
1.6 _{8-PIN SO-EP}
1.4
DERATE
24.4mW/°C
1.2
DERATE
1.0
23.3mW/°C
0.8
0.6
0.4
0.2
0
0 20 40 60 80 100 120 140
TEMPERATURE (°C)
Figure 1. Calculated Maximum Power Dissipation vs. Ambient
Temperature
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