CS8371 데이터 시트보기 (PDF) - ON Semiconductor

부품명

상세내역

일치하는 목록

CS8371

8.0 V/1.0 A, 5.0 V/250 mA Dual Regulator with Independent Output Enables and NOCAP
™

ON Semiconductor 

CS8371

DEFINITION OF TERMS

Dropout Voltage − The input−output voltage differential

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.

Current Limit − Peak current that can be delivered to the

output.

Input Voltage − The DC voltage applied to the input

terminals with respect to ground.

Input Output Differential − The voltage difference

between the unregulated input voltage and the regulated

output voltage for which the regulator will operate.

Line Regulation − The change in output voltage for a

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.

Load Regulation − The change in output voltage for a

change in load current at constant chip temperature.

Long Term Stability − Output voltage stability under

accelerated life−test conditions after 1000 hours with

maximum rated voltage and junction temperature.

Output Noise Voltage − The rms AC voltage at the

output, with constant load and no input ripple, measured

over a specified frequency range.

Quiescent Current − The part of the positive input

current that does not contribute to the positive load current.

The regulator ground lead current.

Ripple Rejection − The ratio of the peak−to−peak input

ripple voltage to the peak−to−peak output ripple voltage.

Temperature Stability of VOUT − The percentage

change in output voltage for a thermal variation from room

temperature to either temperature extreme.

Control

C1*

0.1 µF

VIN

ENABLE1

ENABLE2

GND

VOUT1

VOUT2

8.0 V

5.0 V

Tuner IC

* C1 is required if the regulator is far from the power source filter.

Figure 23. Applications Circuit

APPLICATION NOTES

With seperate control of each output channel, the CS8371

is ideal for applications where each load must be switched

independently. In an automotive radio, the 8.0 V output

drives the displays and tape drive motors while the 5.0 V

output supplies the Tuner IC and memory.

Stability Considerations/NOCAP

Normally a low dropout or quasi−low dropout regulator

(or any type requiring a slow lateral PNP in the control loop)

necessitates a large external compensation capacitor at the

output of the IC. The external capacitor is also used to curtail

overshoot, determine startup delay time and load transient

response.

Traditional LDO regulators typically have low unity gain

bandwidth, display overshoot and poor ripple rejection.

Compensation is also an issue because the high frequency

load capacitor value, ESR (Equivalent Series Resistance)

and board layout parasitics all can create oscillations if not

properly accounted for.

NOCAP is an ON Semiconductor exclusive output stage

which internally compensates the LDO regulator over

temperature, load and line variations without the need for

an expensive external capacitor. It incorporates high gain

(>80 dB) and large unity gain bandwidth (>100 kHz) while

maintaining many of the characteristics of a single−pole

amplifier (large phase margin and no overshoot).

NOCAP is ideally suited for slow switching or steady

loads. If the load displays large transient current

requirements, such as with high frequency microprocessors,

an output storage capacitor may be needed. Some large

capacitor and small capacitor ESR values at the output may

http://onsemi.com

147

Share Link: