MC33269

Part: MC33269 / NCV33269 — onsemi

Type: Low Dropout Linear Voltage Regulator (Fixed and Adjustable)

Description: 800 mA positive low-dropout regulator with 1.0 V typical dropout at 500 mA, available in 3.3 V, 3.5 V, 5.0 V, 12 V and adjustable output versions, with current limiting and thermal shutdown.

Operating Conditions:

• Input voltage: up to 20 V (Vin − Vout of 1.25 V to 15 V at 500 mA, or 1.35 V to 10 V at 800 mA, per the output voltage test conditions)
• Operating ambient temperature: -40 to +125 °C (MC33269 and NCV33269)
• Output capacitor: at least 10 μF with ESR between 0.2 Ω and 10 Ω required for stability

Absolute Maximum Ratings:

• Max supply input voltage: 20 V
• Max junction temperature (operating): -40 to +150 °C
• Storage temperature: -55 to +150 °C
• ESD: 4000 V HBM, 400 V MM

Key Specs:

• Output voltage accuracy (Iout = 10 mA, TA = 25 °C): 3.3 V version 3.27–3.33 V; 5.0 V version 4.95–5.05 V
• Adjustable reference voltage (Iout = 10 mA, Vin − Vout = 2.0 V, TA = 25 °C): 1.235 / 1.25 / 1.265 V (min/typ/max)
• Dropout voltage: 1.0 V typ, 1.25 V max at 500 mA; 1.1 V typ, 1.35 V max at 800 mA
• Line regulation: 0.3 % max (Iout = 10 mA, Vin = Vout + 1.5 V to 20 V, TA = 25 °C)
• Load regulation: 0.5 % max (Vin = Vout + 3.0 V, Iout = 10 mA to 800 mA, TA = 25 °C)
• Ripple rejection: 55 dB min (10 Vpp, 120 Hz, Iout = 500 mA)
• Current limit: 800 mA min
• Quiescent current (fixed output): 5.5 mA typ, 8.0 mA max (1.5 V ≤ Vout ≤ 3.5 V)
• Minimum load current (adjustable version): 8.0 mA
• Adjustment pin current: 120 μA max
• Thermal shutdown: typically 170 °C, no hysteresis

Features:

• 3.3 V, 3.5 V, 5.0 V, 12 V and adjustable versions
• 1.0 V dropout
• Output current in excess of 800 mA
• Thermal protection and short-circuit protection
• Output trimmed to 1.0 % tolerance
• NCV prefix: AEC-Q100 qualified and PPAP capable for automotive use
• Pb-free devices

Applications:

• Low input voltage precision voltage regulation
• Current regulator
• Battery backed-up power supply
• Digitally controlled voltage regulator

Package:

• DPAK (Case 369C), 3-pin
• SO-8 (Case 751)
• SOT-223 (Case 318E)
• TO-220 (Case 221A/221AB)

• Space Saving DPAK, SO -8 and SOT -223 Power Packages
• 3.3 V, 3.5 V, 5.0 V , 12 V and Adjustable Versions 2.85 V version available as MC34268
• 1.0 V Dropout
• Thermal Protection
• Output Current in Excess of 800 mA
• Short Circuit Protection
• NCV Prefix for Automotive and Other Applications Requiring Unique Site and Control Change Requirements; AEC -Q100 Qualified and PPAP Capable
• Output Trimmed to 1.0% Tolerance
• These are Pb -Free Devices

Figures 11 through 15 are typical application circuits. The output current capability of the regulator is in excess of 800 mA, with a typical dropout voltage of less than 1.0 V. Internal protective features include current and thermal limiting.

• The MC33269 requires an external output capacitor for stability. The capacitor should be at least 10 m F with an equivalent series resistance (ESR) of less than 10 W but greater than 0.2 W over the anticipated operating temperature range. With economical electrolytic capacitors, cold temperature operation can pose a problem. As temperature decreases, the capacitance also decreases and the ESR increases, which could cause the circuit to oscillate. Also capacitance and ESR of a solid tantalum capacitor is more stable over temperature. The use of a low ESR ceramic capacitor placed within close proximity to the output of the device could cause instability.

supply input filter with long wire lengths. This will reduce the circuit's sensitivity to the input line impedance at high frequencies. A 0.33 m F or larger tantalum, mylar, ceramic, or other capacitor having low internal impedance at high frequencies should be chosen. The bypass capacitor should be mounted with shortest possible lead or track length directly across the regulator's input terminals. Applications should be tested over all operating conditions to insure stability.

** An input bypass capacitor is recommended to improve transient response or if the regulator is connected to the

An input capacitor is not necessary for stability, however it will improve the overall performance.

Figure 11. Typical Fixed Output Application

Figure 13. Current Regulator

The Schottky diode in series with the ground leg of the upper regulator shifts its output voltage higher by the forward voltage drop of the diode. This will cause the lower device to remain off until the input voltage is removed.

Figure 14. Battery Backed -Up Power Supply

Internal thermal limiting circuitry is provided to protect the integrated circuit in the event that the maximum junction temperature is exceeded. When activated, typically at 170 ° C, the output is disabled. There is no hysteresis built into the thermal limiting circuit. As a result, if the device is overheating, the output will appear to be oscillating. This feature is provided to prevent catastrophic failures from accidental device overheating. It is not intended to be used as a substitute for proper heat -sinking.

Figure 14. Battery Backed -Up Power Supply

$$V_{out} = 1.25 \left(1 + \frac{R2}{R1}\right) + I_{Adj} R2$$

***C Adj is optional, however it will improve the ripple rejection. The MC34269 develops a 1.25 V reference voltage between the output and the adjust terminal. Resistor R1, operates with constant current to flow through it and resistor R2. This current should be set such that the Adjust Pin current causes negligible drop across resistor R2. The total current with minimum load should be greater than 8.0 mA.

Figure 12. Typical Adjustable Output Application

R2 sets the maximum output voltage. Each transistor reduces the output voltage when turned on.

Figure 15. Digitally Controlled Voltage Regulator

Stresses exceeding those listed in the Maximum Ratings table may damage the device. If any of these limits are exceeded, device functionality should not be assumed, damage may occur and reliability may be affected.

ELECTRICAL CHARACTERISTICS (C O = 10 m F, T A = 25 ° C, for min/max values T A = -40 ° C to +125 ° C, unless otherwise noted.)

Figure 1. Internal Schematic

Figure 2. Dropout Voltage versus Output Load Current

Figure 4. Dropout Voltage versus Temperature

Figure 3. Transient Load Regulation

Figure 5. MC33269 -XX Output DC Current versus Input -Output Differential Voltage

Figure 6. MC33269 Ripple Rejection versus Frequency

Figure 7. MC33269 -ADJ Ripple Rejection versus Frequency

Figure 8. SOP -8 Thermal Resistance and Maximum Power Dissipation versus P.C.B. Copper Length

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Figure 9. DPAK Thermal Resistance and Maximum Power Dissipation versus P.C.B. Copper Length

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Figure 10. SOT -223 Thermal Resistance and Maximum Power Dissipation versus P.C.B. Copper Length

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