Rainbow Electronics MAX6796 - Manual (Page 12)

MAX6791–MAX6796
High-Voltage, Micropower, Single/Dual Linear
Regulators with Supervisory Functions
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Detailed Description
The MAX6791–MAX6796 ultra-low-quiescent-current,
single-/dual-output, high-input-voltage linear regulators
operate from 5V to 72V. The MAX6791–MAX6794 fea-
ture dual regulators that deliver up to 150mA of load
current per output. One output is available with preset
output-voltage options (+1.8V, +2.5V, +3.3V, and
+5.0V) and can be adjusted to any voltage between
+1.8V to +11V using an external resistive-divider at
SET1. The other output provides a fixed 5V output volt-
age. The MAX6795/MAX6796 feature a single regulator
that delivers up to 300mA of current with preset output-
voltage options (+1.8V, +2.5V, +3.3V, and +5.0V) or
can be adjusted to any voltage between +1.8V to +11V.
All devices include an integrated µP reset circuit with a
fixed/adjustable reset and watchdog timeout period.
The MAX6791–MAX6796 monitor OUT/OUT1 and
assert a reset output when the output falls below the
reset threshold.
Regulators
The single and dual regulators accept an input voltage
from 5V to 72V. The MAX6791–MAX6796 offer fixed
preset output voltages of +1.8V, +2.5V, +3.3V, and
+5V, or an adjustable output voltage of +1.8V to +11V,
selected using an external resistive-divider network
connected between OUT1/OUT, SET1/SET, and GND
(see Figure 1). In addition to an adjustable output, the
MAX6791–MAX6794 feature a fixed 5V output voltage.
Reset Output
The reset output is typically connected to the reset
input of a µP. A µP’s reset input starts or restarts the µP
in a known state. The MAX6791–MAX6796 supervisory
circuits provide the reset logic output to prevent code-
execution errors during power-up, power-down, and
brownout conditions (see the Typical Application
Circuit). RESET changes from high to low whenever the
monitored output voltage drops below the reset thresh-
old voltage or the watchdog timeout expires. Once the
monitored voltage exceeds its respective reset thresh-
old voltage, RESET remains low for the reset timeout
period, then goes high.
Pin Description (continued)
PIN
MAX6791/
MAX6792
MAX6793/
MAX6794
MAX6795/
MAX6796
NAME FUNCTION
— 10
10, 13, 14,
15
N.C. Not Internally Connected
— — 1, 2 OUT
Regulator Output. Fixed +5V, +3.3V, +2.5V, +1.8V, or adjustable output
(+1.8V to +11V). Connect a 10µF (min) capacitor from OUT to GND.
— — 3 SET
Feedback Input for Setting the OUT Voltage. Connect SET to GND to select the
preset output voltage. Connect to an external resistive-divider for adjustable
output operation.
— — 20 ENABLE
Active-High Enable Input. Drive ENABLE high to turn on the regulator. ENABLE
is internally connected to ground through a 0.5µA current sink.
— — — EP
Exposed Pad. EP is internally connected to GND. Connect EP to the ground
plane to provide a low thermal-resistance path from the IC junction to the PC
board. Do not use as the electrical connection to GND.