LM2931CD2T ON Semiconductor, LM2931CD2T Datasheet - Page 8

• Manufacturer Part Number: LM2931CD2T
• Description: IC REG LDO 100MA ADJ D2PAK-5
• Manufacturer: ON Semiconductor

Specifications of LM2931CD2T

• Regulator Topology: Positive Adjustable
• Voltage - Output: 2.7 ~ 29.5 V
• Voltage - Input: Up to 40V
• Voltage - Dropout (typical): 0.16V @ 100mA
• Number Of Regulators: 1
• Current - Output: 100mA
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: TO-263-5, D²Pak (5 leads + Tab), TO-263BA
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Current - Limit (min): -
• Other names: LM2931CD2TOS

protection features making them essentially blow−out
proof. These features include internal current limiting,
thermal shutdown, overvoltage and reverse polarity input
protection, and the capability to withstand temporary
power−up with mirror−image insertion. Typical application
circuits for the fixed and adjustable output device are shown
in Figures 17 and 18.
regulator is located an appreciable distance (≥ 4″) from the
supply input filter. This will reduce the circuit’s sensitivity
to the input line impedance at high frequencies.
thus requires an external output capacitor for stability. The
capacitance value required is dependent upon the load
current, output voltage for the adjustable regulator, and the
type of capacitor selected. The least stable condition is
encountered at maximum load current and minimum output
voltage. Figure 22 shows that for operation in the “Stable”
region, under the conditions specified, the magnitude of the
output capacitor impedance |Z
The LM2931 series regulators are designed with many
The input bypass capacitor C
This regulator series is not internally compensated and
1.240
1.220
1.200
1.180
1.160
18.5
Figure 15. Reference Voltage versus Output Voltage
14
0
3.0
Figure 13. Line Regulation
6.0
V
O
, OUTPUT VOLTAGE (V)
t, TIME (10 ms/DIV)
9.0
O
| must not exceed 0.4 W. This
12
in
is recommended if the
15
LM2931C Adjustable
I
V
T
O
A
in
= 10 mA
= 25°C
APPLICATIONS INFORMATION
= V
18
V
R
C
C
T
out
A
out
L
O
O(ESR)
= 25°C
= 500 W
= 100 mF
+ 1.0 V
= 5.0 V
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http://onsemi.com
= 0.3 W
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8
limit must be observed over the entire operating temperature
range of the regulator circuit.
operation can pose a serious stability problem. As the
electrolyte freezes, around − 30°C, the capacitance will
decrease and the equivalent series resistance (ESR) will
increase drastically, causing the circuit to oscillate. Quality
electrolytic capacitors with extended temperature ranges of
−40° to +85°C and − 55° to +105°C are readily available.
Solid tantalum capacitors may be a better choice if small size
is a requirement, however, the maximum ⏐Z
temperature must be observed.
linearly proportional to ⏐Z
frequency roll−off point of the circuit. Operation in the area
titled “Marginally Stable” will cause the output of the
regulator to exhibit random bursts of oscillation that decay
in an under−damped fashion. Continuous oscillation occurs
when operating in the area titled “Unstable”. It is suggested
that oven testing of the entire circuit be performed with
maximum load, minimum input voltage, and minimum
ambient temperature.
100
With economical electrolytic capacitors, cold temperature
Note that in the stable region, the output noise voltage is
2.6
2.5
2.4
2.3
2.2
2.1
2.0
0
0
LM2931C Adjustable
I
V
T
O
A
in
= 10 mA
= 25°C
= V
3.0
Figure 16. Output Inhibit−Thresholds
out
+ 1.0 V
Figure 14. Load Regulation
6.0
versus Output Voltage
V
O
, OUTPUT VOLTAGE (V)
9.0
t, TIME (10 ms/DIV)
O
⏐
.
In effect, C
12
15
Output “On"
O
V
V
C
C
C
T
dictates the high
18
A
in
out
in
O
O(ESR)
= 25°C
= 14 V
O
= 1000 mF
= 100 mF
= 5.0 V
Output “Off"
⏐ limit over
= 0.3 W
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