CS8141YDPSR7 ON Semiconductor, CS8141YDPSR7 Datasheet - Page 12

• Manufacturer Part Number: CS8141YDPSR7
• Description: IC REG LDO LIN 500MA 5V D2PAK-7
• Manufacturer: ON Semiconductor

Specifications of CS8141YDPSR7

• Regulator Topology: Positive Fixed
• Voltage - Output: 5V
• Voltage - Input: 7 ~ 26 V
• Voltage - Dropout (typical): 1.25V @ 500mA
• Number Of Regulators: 1
• Current - Output: 500mA
• Current - Limit (min): 700mA
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: TO-263-7, D²Pak (7 leads + Tab), TO-263CA
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: CS8141YDPSR7OS

helps determine three main characteristics of a linear
regulator: start−up delay, load transient response and loop
stability.
availability, size and temperature constraints. A tantalum or
aluminum electrolytic capacitor is best, since a film or
ceramic capacitor with almost zero ESR can cause
instability. The aluminum electrolytic capacitor is the least
expensive solution, but, if the circuit operates at low
temperatures (−25°C to −40°C), both the value and ESR of
the capacitor will vary considerably. The capacitor
manufacturers data sheet usually provides this information.
should work for most applications, however it is not
necessarily the optimized solution.
application, start with a tantalum capacitor of the
recommended value and work towards a less expensive
alternative part.
capacitor of the recommended value in an environmental
chamber at the lowest specified operating temperature and
monitor the outputs with an oscilloscope. A decade box
connected in series with the capacitor will simulate the
higher ESR of an aluminum capacitor. Leave the decade box
outside the chamber, the small resistance added by the
longer leads is negligible.
increase the load current slowly from zero to full load while
observing the output for any oscillations. If no oscillations
are observed, the capacitor is large enough to ensure a stable
design under steady state conditions.
the decade box and vary the load current until oscillations
appear. Record the values of load current and ESR that cause
the greatest oscillation. This represents the worst case load
conditions for the regulator at low temperature.
The output or compensation capacitor C
The capacitor value and type should be based on cost,
The value for the output capacitor C
To determine an acceptable value for C
Step 1: Place the completed circuit with a tantalum
Step 2: With the input voltage at its maximum value,
Step 3: Increase the ESR of the capacitor from zero using
*C1 is required if regulator is located far from the power source filter.
**C2 is required for stability.
***R ≤ 80 kW.
Ignition
Battery
STABILITY CONSIDERATIONS
C
0.1 mF
(optional)
0.1 mF
1
*
V
ENABLE
DELAY
2
IN
shown in Figure 22
2
for a particular
2
CS8140
in Figure 22
Figure 22. Application Diagram
GND
CS8140, CS8141
http://onsemi.com
RESET
V
WDI
OUT
12
step 3 and vary the input voltage until the oscillations
increase. This point represents the worst case input voltage
conditions.
with the next smaller valued capacitor. A smaller capacitor
will usually cost less and occupy less board space. If the
output oscillates within the range of expected operating
conditions, repeat steps 3 and 4 with the next larger standard
capacitor value.
various loads at several frequencies to simulate its real
working environment. Vary the ESR to reduce ringing.
operating temperature. Vary the load current as instructed in
step 5 to test for any oscillations.
ESR is found, a safety factor should be added to allow for the
tolerance of the capacitor and any variations in regulator
performance. Most good quality aluminum electrolytic
capacitors have a tolerance of ± 20% so the minimum value
found should be increased by at least 50% to allow for this
tolerance plus the variation which will occur at low
temperatures. The ESR of the capacitor should be less than
50% of the maximum allowable ESR found in step 3 above.
regulator (Figure 23) is:
P D(max) + V IN(max) * V OUT(min) I OUT(max) ) V IN(max) I Q
where:
R***
Step 4: Maintain the worst case load conditions set in
Step 5: If the capacitor is adequate, repeat steps 3 and 4
Step 6: Test the load transient response by switching in
Step 7: Increase the temperature to the highest specified
Once the minimum capacitor value with the maximum
CALCULATING POWER DISSIPATION IN A SINGLE
The maximum power dissipation for a single output
V
V
I
I
OUT(max)
Q
C
10 mF*
IN(max)
OUT(min)
application, and
I
2
is the quiescent current the regulator consumes at
OUT(max)
*
2.7 kW
is the maximum input voltage,
is the maximum output current for the
OUTPUT LINEAR REGULATOR
is the minimum output voltage,
.
RESET
WATCHDOG
PORT
Microprocessor
V
CC
(1)