CS8481 ON Semiconductor, CS8481 Datasheet - Page 4

• Manufacturer Part Number: CS8481
• Description: Micropower Low Dropout Regulator
• Manufacturer: ON Semiconductor

output.
at which the circuit ceases to regulate against further
reduction in input voltage. Measured when the output
voltage has dropped 100 mV from the nominal value
obtained at 14 V input, dropout voltage is dependent upon
load current and junction temperature.
between the unregulated input voltage and the regulated
output voltage for which the regulator will operate.
terminals with respect to ground.
change in the input voltage. The measurement is made under
conditions of low dissipation or by using pulse techniques
such that the average chip temperature is not significantly
affected.
General
required to operate the internal circuitry is derived from the
standby output, V
current situation and collapses, then V
collapse (see Figure 2).
most conditions it should be connected to V
circuitry that is likely to be subjected to a short circuit, e.g.,
circuitry outside the module, should be connected to V
External Capacitors
CS8481. Without them, the regulator outputs will oscillate.
Actual size and type may vary depending upon the
application load and temperature range. Capacitor effective
series resistance (ESR) is also a factor in the IC stability.
Current Limit − Peak current that can be delivered to the
Dropout Voltage − The input−output voltage differential
Input Output Differential − The voltage difference
Input Voltage − The DC voltage applied to the input
Line Regulation − The change in output voltage for a
The CS8481 is a Micropower dual regulator. All bias
If there is critical circuitry that must remain active under
Output capacitors are required for stability with the
Condition
ENABLE
System
V
V
OUT1
OUT2
V
IN
2.0 V
0.8 V
5.0 V
14 V
0 V
OUT2
Turn
On
. If this output experiences an over
3.3 V
5.0 V
74 V
Dump
Load
34 V
3.3 V
5.0 V
OUT1
Figure 2. Typical Circuit Waveform
Low V
OUT2
DEFINITION OF TERMS
3.0 V
2.4 V
2.4 V
APPLICATION NOTES
IN
will also
http://onsemi.com
. Any
OUT1
30 V
Noise, Etc.
CS8481
.
Line
4
3.3 V
5.0 V
change in load current at constant chip temperature.
accelerated life−test conditions after 1000 hours with
maximum rated voltage and junction temperature.
current that does not contribute to the positive load current,
i.e., the regulator ground lead current.
ripple voltage to the peak−to−peak output ripple voltage.
delivered by the outPut when forced to 0 V.
change in output voltage for a thermal variation from room
temperature to either temperature extreme.
Worst−case is determined at the minimum ambient
temperature and maximum load expected.
value above the minimum. One possible purpose of this
would be to maintain the output voltages during brief
conditions of negative input transients that might be
characteristic of a particular system.
expected in the system. To maintain regulator stability down
to −40 C, capacitors rated at that temperature must be used.
REGULATOR s is available in the SMART REGULATOR
application note, “Compensation for Linear Regulators,”
document number SR003AN/D, available through the
Literature Distribution Center or via our website at
http://www.onsemi.com.
Load Regulation − The change in output voltage for a
Long Term Stability − Output voltage stability under
Quiescent Current − The part of the positive input
Ripple Rejection − The ratio of the peak−to−peak input
Short Circuit Current Limit − Peak current that can be
Temperature Stability of V
Output capacitors can be increased in size to any desired
Capacitors must also be rated at all ambient temperatures
More information on capacitor selection for SMART
V
Circuit
Short
OUT1
0 V
3.3 V
5.0 V
V
Circuit
Short
OUT2
0 V
0 V
3.3 V
5.0 V
OUT
Shutdown
Thermal
− The percentage
14 V
3.3 V
5.0 V
Turn
Off
0 V