LDFM50DT-TR STMicroelectronics, LDFM50DT-TR Datasheet - Page 10

• Manufacturer Part Number: LDFM50DT-TR
• Description: Low Dropout Controllers - LDO 500mA VLDR 300mV 2.5V to 16V LDFM
• Manufacturer: STMicroelectronics

Specifications of LDFM50DT-TR

• Rohs: yes
• Input Voltage Max: 16 V
• Output Voltage: 5 V
• Output Current: 500 mA
• Output Type: Adjustable
• Maximum Operating Temperature: + 125 C
• Mounting Style: Through Hole
• Package / Case: DPAK
• Input Voltage Min: 2.5 V
• Minimum Operating Temperature: - 40 C

Application information
6
6.1
6.1.1
6.1.2
6.2
6.3
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Application information
External capacitors
The LDFM requires external capacitors for regulator stability. These capacitors must be
selected to meet the requirements of minimum capacitance and equivalent series resistance
(see
possible to the relative pins.
Input capacitor
An input capacitor with a minimum value of 1 µF is required with the LDFM. This capacitor
must be located a distance of not more than 0.5" from the input pin of the device and
returned to a clean analog ground. Any good quality ceramic capacitors can be used for this
capacitor.
Output capacitor
It is possible to use ceramic capacitors but the output capacitor must meet the requirements
for minimum amount of capacitance and E.S.R. (equivalent series resistance) value.
A minimum capacitance of 2.2 µF is a good choice to guarantee the stability of the regulator.
However, other C
allowable ESR range as a function of the output capacitance.
The output capacitor must maintain its ESR in the stable region over the full operating
temperature range to assure stability. Also, capacitor tolerance and variation with
temperature must be kept in consideration in order to assure the minimum amount of
capacitance at all times.
Enable pin operation
The Enable pin can be used to turn OFF the regulator when pulled down, so drastically
reducing the current consumption. When the enable feature is not used, this pin must be
tied to V
signal source used to drive the Enable pin must be able to swing above and below the
specified thresholds listed in the electrical characteristics section (V
must not be left floating because it is not internally pulled down/up.
Power Good
The LDFM features an open drain Power Good (PG) pin to sequence external supplies or
loads and to provide fault detection. This pin requires an external resistor (R
high when the output is within the PG tolerance window. Typical values for this resistor range
from 10 k to 100 k.
Figure 26
IN
to keep the regulator output ON at all times. To assure proper operation, the
and
OUT
27
values can be used according to
). It is advisable to locate the input/output capacitors as close as
Doc ID 023585 Rev 1
Figure 26
and
EN
27,
). The Enable pin
showing the
LDFM, LDFM50
PG
) to pull PG