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2022-09-15 14:32:14
The L4987 series extremely low pressure pressure pressure pressure pressure pressure pressure suppression and release control signs
Very low voltage drop (0.25V typical)
Exit control logo
Very low static current (typical value. The closing mode is 90 μA, and the 500μA mode is in the opening mode)
Output current is as high as 200 mia
Logical control electron
Close
output voltage 3V, 5V 8.7V 12V
Internal current And thermal limit
Stability is only 2.2 μF
25 ° C, you can choose ± 2%
Power supply voltage suppression: 70 dB (typical value)
] Explanation
L4987 is a very low voltage downturn regulator in PPAK. The extremely low drop voltage (in 200 mAh) and very low static current make it particularly suitable for low noise, low power consumption applications, and battery power supply systems. This 40V input and reserve protection makes it an automotive application. Close logic control function available (PIN2, TTL compatibility). This means that when the device is a local regulator, some boats can be on standby, and the total number of people can reduce power consumption. The regulatory agency adopts an output pins of the logical signal (the circuit of the collector) When the low -pass transistor is saturated, this signal can be used to prevent the pop -up phenomenon of the car radio. In the battery power supply system (mobile phone, you can use the mark to monitor the battery charging status supervisor.
The electrical characteristics of L4987CPT30 (refer to test circuit, VI u003d 6 V, output output u003d 5 mAh, TJ u003d 25 degrees C, CI u003d 0.1 μF, CO u003d 2.2 μF, unless there are regulations)
The electrical characteristics of L4987CPT50 VI u003d 8 V, output u003d 5mA, TJ u003d 25OC, CI u003d 0.1 μF, CO u003d 2.2 μF, unless there are other regulations)
L4987CPT87's electrical characteristics (reference test test test Circuit, vi u003d 11.7V, output u003d 5mA, TJ u003d 25OC, CI u003d 0.1 μF, CO u003d 2.2 μF, unless there are other regulations)
Typical performance characteristics ( Unless there are other regulations, TJ u003d 25OC, CIN u003d COUT u003d 1 μF)
L4987CPT30 Application Tips
How to use the control mark as the output exceeding the regulations. A ""out"" adjustment condition may come from:
(1) low input voltage (vin≤vout+vdrop)
(2) current limit
(3) heat restriction
FIG. 1 to Figure 2 shows the output voltage and control signs and input voltage and temperature. There is no delayed implementation; therefore, the response of VOUT and VFLAG should rise or fall down. The control sign is an open collector that requires an external pull -up resistor. This may be connected to the regulator output (Figure 3) or some other power supply voltage (Figure 4). Using the regulator output can prevent the ""high"" on the invalid flag, if it is pulled to the external voltage voltage when the regulator is input, the external voltage voltage is reduced to less than 2V (Figure 5). Regarding the pull -up resistor, the value must be selected correctly according to the following suggestions. When ""low"