MAX5087BATE/V+T Maxim Integrated Products, MAX5087BATE/V+T Datasheet - Page 8

• Manufacturer Part Number: MAX5087BATE/V+T
• Description: IC REG LDO 5V/ADJ 400MA 16-TQFN
• Manufacturer: Maxim Integrated Products

Specifications of MAX5087BATE/V+T

• Regulator Topology: Positive Fixed or Adjustable
• Voltage - Output: 5V, 2.5 ~ 11 V
• Voltage - Input: 6.5 ~ 45 V
• Voltage - Dropout (typical): 0.9V @ 400mA
• Number Of Regulators: 1
• Current - Output: 400mA (Min)
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 16-TQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Limit (min): -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

The MAX5087 high-voltage linear regulator includes an
integrated µP reset circuit with an adjustable reset time-
out period (see the Adjustable Reset Timeout Period
(CT) section). The device guarantees a 400mA load
current and is available with a preset output voltage of
3.3V (MAX5087A) or 5V (MAX5087B). Both devices can
be configured to provide an adjustable output voltage
from 2.5V to 11V. The internal reset circuit monitors the
regulator output voltage and asserts RESET low when the
regulator output falls below the reset threshold voltage.
Other features include an enable (regulator control input),
21µA (max) shutdown current, short-circuit protection
(see the Output Short-Circuit Current Limit section), and
thermal shutdown (see the Thermal Protection section).
The MAX5087 accepts an input voltage range from
6.5V to 45V and offers a fixed output voltage of 3.3V or
5V. For an adjustable output voltage operation, use an
external resistive divider network connected between
OUT, SET, and GND (see Figure 2).
EN is a logic-level enable input that turns the device
on/off. Drive EN high to turn on the device and drive EN
low to place the device in shutdown. The MAX5087
draws 11µA (typ) of supply current when in shutdown.
EN withstands voltages up to +45V, allowing EN to be
connected to IN for an always-on operation.
The 3.3V (MAX5087A) and 5V (MAX5087B) output volt-
age versions connect OUTSENSE for load voltage
sensing. Leave OUTSENSE open when using
adjustable output voltage version.
A supervisor circuit is fully integrated in the MAX5087
and uses the same reference voltage as the regulator.
RESET goes low if V
voltage threshold, and remains low at least for the time-
out period after V
threshold.
The MAX5087 features a user-adjustable reset timeout.
Connect a capacitor from CT to GND to set the reset
45V, 400mA, Low-Quiescent-Current
Linear Regulator with Adjustable Reset Delay
8
_______________________________________________________________________________________
Adjustable Reset Timeout Period (CT)
Remote Sensing (OUTSENSE)
OUT
OUT
Detailed Description
rises above the reset voltage
drops below the preset output
Reset Output ( RESET )
Enable Input (EN)
Regulator
timeout period (see Figure 2) and use the following
equation to calculate the timeout period:
where C
nected from CT to GND.
When the junction temperature exceeds T
an internal thermal sensor signals the shutdown logic,
which turns off the pass transistor, allowing the IC to
cool. The thermal sensor turns the pass transistor on
again after the IC’s junction temperature cools by 25°C,
resulting in a cycled output during continuous thermal-
overload conditions. Thermal protection protects the
MAX5087 in the event of fault conditions. During contin-
uous operation, do not exceed the absolute maximum
junction temperature rating of T
The MAX5087 features a current limit. The output can
be shorted to GND for an indefinite period of time (for
V
output short-circuit protection is only guaranteed for
V
Figure 2. Setting the Adjustable Output Voltage
IN
IN
< 14V.
< 14V) without damage to the device. Continuous
OFF
6.5V TO 45V
47μF
ON
C
CT
CT
TO μP
Output Short-Circuit Current Limit
is the value of the external capacitor con-
t
RP
IN
EN
RESET
CT
= C
CT
MAX5087
x 0.6175 x 10
GND
OUTSENSE
Thermal Protection
OUT
J
SET
= +150°C.
V
V
OUT
SET
6
= 1.235V
= V
(s)
R1
R2
SET
2.5V TO 11V
J
(1 + R1 / R2)
= +175°C,
15μF