Features: · Low current consumption
Operating current: Typ. 1.0 mA, Max. 1.8 mA (3.0 V)
· Output voltage: 2.0 to 6.0 V (0.1 V step)
· Output voltage accuracy: ±2.0%
· Output current:
50mA capable (3.0 V output product, VIN=5 V) Note1
75mA capable (5.0 V output product, VIN=7 V) Note1
· Dropout voltage
Typ. 120 mV (VOUT = 5.0 V, IOUT = 10 mA)
· Power-off function: Polarity for power-off switch or removal of the power-off function can be selected.
· Short-circuit protection: Product with/without short-circuit protection is available. Short-circuited current : 40 mA typ. for products with protection
· Packages: SOT-23-5 (Package drawing code : MP005-A)
SOT-89-5 (Package drawing code : UP003-A)
SOT-89-3 (Package drawing code : UP005-A)
TO-92 (Package drawing code : YF003-A)
Note1 Power dissipation of the package should be taken into account when the output current is large.
Application· Power source for battery-powered devices
· Power source for personal communicationdevices
· Power source for home electric/electronicappliancesSpecifications
| Item |
Symbol |
Absolute Maximum Rating |
Units |
| Input voltage |
VON/OFF |
VIN
VSS-0.3 to 18 |
18 V
V |
| Output voltage |
VOUT |
VSS-0.3 to VIN+0.3 |
V |
Power dissipation
|
PD |
250(SOT-23-5),500 (SOT-89-5)
500(SOT-89-3),400(TO-92) |
mW |
| Operating temperature range |
Topr |
-40 to +85 |
°C |
| Storage temperature range |
Tstg |
-40 to +125 |
°C |
mW
Description1. Basic operation
Figure 9 shows the block diagram of the S-812Cseries.The error amplifier compares a reference voltage Vref with a part of the output voltage divided by the feedback resistors Rs and Rf, and supplies the gatevoltage to the output transistor, necessary to ensure certain output voltage independent from change of input voltage and temperature.
2. Output transistor
The S-812C Series uses a Pch MOS transistor as the output transistor.The voltage at VOUT must not exceed VIN+0.3V. When the VOUT voltage becomes higher than that of VIN, reverse current flows and may break the regulator since a parasitic diode between VOUT and VIN exists inevitably.
3. Power-off function (ON/OFF pin)
The ON/OFF pin controls the start and stop of the regulation operation in S-812C .When the ON/OFF pin is set to power-off level, halting whole internal circuit and turning off the Pch MOSFET between VIN and VOUT, current consumption is drastically reduced. The voltage of the VOUT pin becomes VSS level due to the internal resistance divider of several MW between VOUT and VSS. The ON/OFF pin should not be left afloat since no pull-up nor pull-down is made internally as shown in figure 10. Note that the current consumption increases if a voltage between 0.3V and VIN-0.3V is applied to the ON/OFF pin. When the power-off function is not used, connect the pin to the VIN pin in case of positive logicand to the VSS pin in case of negative logic.
4. Short-circuit protection
Installation of the short-circuit protection which protects the output transistor against short-circuit between VOUT and VSS can be selected in the S-812C series. The short-circuit protection controls output current as shown in the typical characteristics, (1) OUTPUT VOLTAGE versus OUTPUT CURRENT, and suppresses output current at about 40 mA even if VOUT and VSS pins are short-circuited. The short-circuit protection can not at the same time be a thermal protection. Attention should be paid to the Input voltage and the load current under the actual condition so as not to exceed the power dissipation of thepackage including the case for short-circuit. When the output current is large and the difference between input and output voltage is large even if not shorted, the short-circuit protection may work and the output current is suppressed to the specified value. Products without short-circuit protection in S-812C can provide comparatively large current by removing a short-circuit protection.
S-812C Data Sheet
