ST715 STMICROELECTRONICS | Alldatasheet
Document overview
- Manufacturer or author: Provided By ALLDATASHEET.COM(FREE DATASHEET DOWNLOAD SITE)
- PDF pages: 24
Technical content
Datasheet sections
- 1 Diagram
- 2 Pin configuration
- 3 Maximum ratings
- 4 Electrical characteristics
- 5 Output voltage selection for adjustable version
- 5.1 External capacitor requirements
- 5.2 Power dissipation and junction temperature
- 6 Typical application
- 7 Typical performance characteristics
- 8 Package mechanical data
- 9 Packaging mechanical data
- 10 Revision history
Features
- 2.5 V to 24 V input voltage
- Low-dropout voltage (500 mV typ. at 85 mA)
- Very low quiescent current (3.8 µA typ. at full load)
- 85 mA guaranteed output current
- Output voltages available on request: from 1.2 V to 5.0 V with 100 mV step and adjustable
- Compatible with ceramic output capacitors from 0.47 µF to 10 µF
- Internal current limit
- Packages: SOT23-5L, SOT323-5L and DFN8 (3x3 mm)
- Temperature range: from -40 °C to 125 °C
Applications
- Mobile phones
- Personal digital assistant (PDAs)
- Cordless phones and similar battery-powered systems
Description
The ST715 is a high voltage, ultra low quiescent current and low drop linear regulator capable of providing an output current in excess of 85 mA. The device operates over an input voltage range from 2.5 V to 24 V, and it is stable with output ceramic capacitors. Fault condition protection includes short-circuit current limitation. The ultra low quiescent current of 3.8 µA at full load makes it highly suitable for low power applications and battery-powered systems. The wide input voltage range makes the ST715 an ideal solution for low power industrial applications. The ST715 is available in SOT23-5, SOT323-5L or DFN8 (3x3 mm) 8 leads. SOT23-5L DFN8 (3x3 mm) SOT323-5L Table 1. Device summary
1 Diagram
Figure 1. Block diagram (fixed version) Figure 2. Block diagram (adjustable version)
2 Pin configuration
Figure 3. Pin connection (top view) Table 2. Pin description (DFN8 3x3 mm) Table 3. Pin description (SOT23-5L/SOT323-5L)
3 Maximum ratings
Note: Absolute maximum ratings are those values beyond which damage to the device may occur. Functional operation under these conditions is not implied. Table 4. Absolute maximum ratings
- P D is based on an operating temperature of 25 °C or less. It must be derated according to the operating temperature.
Table 5. Thermal data
4 Electrical characteristics
Table 6. Electrical characteristics - adjustable version
200 Hz to 100 kHz, IOUT = 50 mA,
- Turn-on time is time measured between the input just exceeding 90% of its final value and the output voltage just reaching
Table 7. Electrical characteristics - fixed version
- Dropout voltage is the input-to-output voltage difference at whic h the output voltage is 100 mV below its nominal value. This
specification does not apply to output voltages below 2 V.
- Turn-on time is time measured between the input just exceeding 90% of its final value and the output voltage just reaching
Output voltage selection for adjustable version ST715
5 Output voltage selection for adjustable version
The ST715 features an adjustable output voltage due to two external resistors connected as a voltage divider to the FB pin as shown in Figure 4. The output voltage is set by the following equation: Equation 1 VOUT = VFB (1 + R1/R2) where typically VFB = 1.2 V. Choose R2 ≥ 5 kΩ to optimize the quiescent current, accuracy, and high-frequency power supply rejection. The resistor selection is given by the following equation: Equation 2 R 1 = R2 x (VOUT/VFB - 1)
5.1 External capacitor requirements
A 0.1 µF or a larger input bypass capacitor, connected between IN and GND and located close to the device, is recommended. In this manner, the transient response and noise rejection of the power supply, as a whole, improve. A higher value of the input capacitor may be necessary if large, fast-rise-time load transients are present in the application and if the device is several inches far from the power source. The ST715 requires an output capacitor connected between OUT and GND to stabilize the internal control loop. Any capacitor, (including ceramic and tantalum) with a value higher than 0.47 µF, stabilizes this loop.
5.2 Power dissipation and junction temperature
For a reliable operation, junction temperature should not exceed 125 °C. This limits the power dissipation the regulator can handle in any application. To guarantee that the junction temperature is within acceptable limits, calculate the maximum allowable dissipation, P D(max), and the dissipation, PD, which must be less than or equal to PD(max). The maximum power dissipation limit is given by the following equation: Equation 3 PD(max) = (TJMAX - TA) / RthJA where: T JMAX is the maximum allowable junction temperature RthJA is the thermal resistance junction-to-ambient for the package TA is the ambient temperature The regulator dissipation is calculated by the following equation:
ST715 Output voltage selection for adjustable version Equation 4 PD = (VIN - VOUT) x IOUT Power dissipation coming from quiescent current is negligible. The ST715 features the internal current limit. During normal operation, it limits the output current to approximately 350 mA. When the current limit engages, the output voltage scales back linearly until the overcurrent condition ends. Do not exceed the power dissipation ratings of the package.
6 Typical application
Figure 4. Application circuit for fixed version Figure 5. Application circuit for adjustable version
7 Typical performance characteristics
Figure 6. Output voltage vs. temperature Figure 7. Output voltage vs. input voltage Figure 8. Dropout voltage vs. output current Figure 9. C OUT stability region Figure 10. Supply voltage rejection vs. Figure 11. Output noise voltage vs. frequency
8 Package mechanical data
specifications, grade definitions and product status are available at: www.st.com. ECOPACK® is an ST trademark. Figure 16. SOT23-5L drawing
Figure 17. SOT23-5L recommended footprint (dimensions in mm) Table 8. SOT23-5L mechanical data
Figure 18. SOT323-5L drawing
Table 9. SOT323-5L mechanical data
Figure 19. DFN8 (3x3 mm) drawing
Table 10. DFN8 (3x3 mm) mechanical data
Figure 20. DFN8 (3x3 mm) recommended footprint
9 Packaging mechanical data
Figure 21. Tape and reel SOT23-5L drawing
Table 11. SOT23-5L tape and reel mechanical data Table 12. SOT323-xL tape and reel mechanical data
Table 13. DFN8 (3x3 mm) tape and reel mechanical data
Table 14. Document revision history 08-Feb-2008 1 Initial release. 19-Feb-2008 2 Modified: Features on page 1. 22-Sep-2008 3 Modified: DFN8 (3x3 mm) mechanical data 10 on page 23. 26-Nov-2008 4 Modified: Section 5 on page 8. 24-Mar-2010 5 Modified: Table 4 on page 5. 24-Mar-2010 6 Modified: I Q max values Table 6 on page 6 and Table 7 on page 7. 20-May-2010 7 Modified: Table 2 and Table 3 on page 4. Part numbers ST715xx, ST715xx25, ST715xx33 changed to ST715. Added package DFN8 (3 x 3 mm). Updated the title, the features and the description in cover page. Added Section 9: Packaging mechanical data. 21-May-2014 9 Updated Section 8: Package mechanical data.