FAQ Frequently Asked Questions

[Voltage regulator] Is there a way to prevent the output voltagefrom increasing at low current load?

When the load is low, the transistor in the regulator must be of high impedance. There is, however, leakage current in the transistor, so control is not possible when the load is low. As a result, the output voltage increases (for specific values, see the data sheets of respective products).
This symptom cannot be avoided because it is caused by the series regulator configuration. Countermeasures, such as connecting a dummy load resistance, must be taken.

[S-812CXX] The products in SNT-6A(H) packages feature two VIN pins (pins 2 and 5). Do they feature the same functions?

The functions of these pins are the same.
Two VIN pins are provided for promoting heat loss.
The input voltage of the S-812CXX Series is high at 16 Vmax. and the power dissipation of the IC is large,
causing a high temperature. Connect two VIN pins to the board.

[S-817] Can a Voltage Regulator (LDO Regulator) Be Used as a reference voltage?

Series S-817 is superior in input stability and keeps output variation under 5 mV typ. even when output current of Iout=1µA flows during light load. Consequently, the S-817 can be used as a reference voltage of A/D converters and similar devices if input voltage varies. Namely, it covers applications without flowing output current of the regulator.

[S-817] Can a Ceramic Capacitor Be Used as an Output Capacitor?

Series S-817 is an internal phase compensation regulator. It ensures stable operations even when ESR of
the output capacitor is low. This enables to use a low ESR ceramic capacitor. Operating conditions of the
ceramic capacitor are:
Capacitance is 0.1µF or more;
ESR is 30 ohm or less.

[S-817] Is an Input Capacitor or an Output-Capacitor Needed?

need it depending on their own operating conditions.

Briefly explained, the output level enables the phase to be compensated using the output capacitor’s ESR.
This ensures stable operations even if output load varies.
The output capacitor allows customers to connect a ceramic capacitor or which current is 0.1µF and ESR is 30 ohm or less.

Necessity of a capacitor at the input level will be determined based on the input power characteristics. The valid data confirmed on your actual product is of importance.

[S-817] Method Used for Flowing Large Current Using the S-817 Series?

Voltage regulators need an input capacitor or output capacitor at the output level, whereas at the input level, they may not need it depending on their own operating conditions.

Briefly explained, the output level enables the phase to be compensated using the output capacitor’s ESR.
This ensures stable operations even if output load varies.
The output capacitor allows customers to connect a ceramic capacitor or which current is 0.1µF and ESR is 30 ohm or less.

Necessity of a capacitor at the input level will be determined based on the input power characteristics. The valid data confirmed on your actual product is of importance.

[S-814] Can a Ceramic Capacitor Be Used as an Output Capacitor?

A ceramic capacitor can be used in the S-814 as an output capacitor. The S-814 is an internal phase compensation regulator that ensures stable operation even when ESR of the output capacitor is low. This allows to use a low ESR ceramic capacitor. Operating conditions of the ceramic capacitor are:
Capacitance is 0.47µF or more;
ESR is 10 Ω or less.

[S-816] No Problem When any Part other than a Tantalum Electrolytic Capacitor Is Used in the Output Capacitor?

There is a possibility of output being oscillating when using a ceramic capacitor or an OS capacitor whose ESR is low.

To make stabile operation of the S-816 series, it is necessary to use a capacitor that ensures the optimum range of ESR (EQUIVALENT SERIES RESISTANCE). Higher or lower ESR than the specified range may destabilize output and oscillate the circuit. It is recommended that a tantalum electrolytic capacitor be used.

When using a ceramic capacitor or an OS capacitor, it is necessary to add a resistor (in substitution for ESR) to the output capacitor in series.
Resistance of the resistor to be added ranges from 0.1 Ω to 5 Ω or thereabouts. It differs depending upon operating conditions. Be sure to determine it after making a sufficient assessment. The recommended value is approx. 0.3 Ω.

An aluminum electrolytic capacitor may cause oscillation due to increased ESR at low temperatures.
It is necessary to make a sufficient assessment including temperature characteristics.

[S-816] The Reason that Noise Generates at the Regulator Output Pin at an Uncertain Interval?

Noise generating at the regulator output pin at an uncertain interval of several ms to seconds may be attributed to popcorn noise emitted from the external bipolar transistor.

Popcorn noise will be emitted from the bulk operation-type bipolar transistor. Generation of such noise is not attributed to CMOS based S-816 series.

[Voltage Regulator] What’s a Short Current Limit Circuit?

For example, the S-817 series has a short current limit circuit to safeguard the output transistor from shortcircuiting between VOUT-VSS pins. The short current limit circuit controls output current for Vout voltage and keeps output current constant at 40 mA or thereabouts even when shortcircuiting between VOUT-VSSp pins occurs.


Figure 1

Please note that the short current limit circuit does not protect thermal shutdown. Taking into consideration requirements for input voltage and load current including shortcircuit conditions so that any loss in the IC does not exceed the maximum power dissipation.


Figure 2

The short current limit circuit starts functioning to safeguard the output transistor when large current flows and the difference between input and output voltage is large even if not shorted.

[Voltage Regulator] What’s a Low Dropout Voltage Regulator (LDO Regulators) ?

A voltage regulator has an output transistor (also called a pass transistor) using a low ON-resistance transistor. This transistor minimizes the drop of voltage (dropout) of the voltage regulator. Series S-814 and S-818 are low dropout voltage regulators. The dropout voltage to flow current of 60 mA is 0.17 V (typ.) for both series of 5-V output products.

[Voltage Regulator] Applications of Low Dropout Voltage Regulators (LDO Regulators) ?

Low dropout voltage regulators are used in applications where the difference between the input and output voltages is low as well as necessary current is large.

For example, lowdropout voltage regulators meet the requirements for maximizing the battely voltage limit. This is because they can supply constant current even when the input voltage (battery voltage) drops and approximates the output voltage. A reduced dropout voltage brings the same effect as the battery life is prolonged.

[Product Reliability] How is the product life judged?

Acceleration tests, which are included in periodic reliability tests, are performed for a time equivalent to the product life, to judge the endurance of the product.
Voltage acceleration and temperature acceleration are included in the acceleration tests. ABLIC adopts temperature acceleration tests based on the Arrhenius model.
The acceleration factor conforms to JEITA standard EIAJ ED-4701 and is calculated by the following formula.

(Acceleration factor calculation formula) L = exp(Ea/kT2)/exp(Ea/kT1)
L: Acceleration factor
Ea: Energy of activation
k: Boltzmann coefficient
T2: Actual use temperature (absolute temperature)
T1: Acceleration test temperature (absolute temperature)

Specifically, the following conditions are substituted.
Energy of activation 0.5 eV
Boltzmann coefficient 8.617 × 10-5 eV/K
Actual use temperature 40°C
As a result of the above substitution, the acceleration factor at 125°C is shown to be 52 times that at 40°C. In sum,
1,000 hours are equivalent to 5.9 years
2,000 hours are equivalent to 11.8 years.

As shown above, successfully performing reliability tests at 125°C for 2,000 hours assures that the product life is judged to be at least 10 years at the actual use temperature.

[Package] Does the mold resin contain phosphorus?

Inorganic phosphorus is not used in ABLIC products. Organic phosphorus is used in some packages as a resin hardness accelerator.

[Package] Can packages be used when the power dissipation is momentarily exceeded due to rush current?

The power dissipation is the average power per second.
Packages can be used when the average power is within the power dissipation range, even if a large current momentarily flows due to rush current.

[Package] How should the potential of a radiation pad on the rear of a package be kept constant?
HSON(A), SNB(B), SON(B), PLP

Radiation pads on the rear side are affixed to the IC die substrate via silver paste (conductive paste). Radiation pads, therefore, must be used with the potential of the pads being the same as that of the IC die substrate or floating.

*Caution Radiation pads cannot be used as electrodes.

Product Name Subject Package Name Potential of Radiation Pad
S-1131 6-pin HSON(A) VSS or open
S-1170 6-pin HSON(A) VSS or open
S-8355/56/57/58 6-pin SNB(B) VOUT (VDD for VDD separate type) or open
S-8821 6-pin SNB(B) VSS or open
S-8261 6-pin SNB(B) VDD or open
S-8242 6-pin SNB(B) VDD or open
S-8424A 8-pin SON(B) VSS or open
S-8425 8-pin SON(B) VSS or open
S-83M355/356 PLP-8B See the data sheet.
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