L4949ED-E_V01 STM | Alldatasheet
Document overview
- Manufacturer or author: Provided By alldatasheet.com(free datasheet download site)
- PDF pages: 19
Technical content
Datasheet sections
- 1 Block diagram and pin descripti on
- 2 Electrical specifications
- 2.1 Absolute maximum ratings
- 2.2 Thermal data
- 2.3 Electrical characteristics
- 3 Application information
- 3.1 Supply voltage transient
- 3.2 Functional description
- 3.3 Voltage regulator
- 3.4 Preregulator
- 3.5 Reset circuit
- 3.6 Sense comparator
- 4 Package and packing information
- 4.1 ECOPACK ® packages
- 4.2 SO-8 TP package information
- 4.3 SO-20 TP package information
- 5 Revision history
Features
AEC-Q100 qualified ECOPACK®: lead free and RoHS compliant Operating DC supply voltage range 5 V - 28 V Transient supply voltage up to 40 V Extremely low quiescent current in standby High precision standby output voltage 5V±1% Output current capability up to 100 mA Very low dropout voltage less than 0.5 V Reset circuit sensing the output voltage Programmable reset pulse delay with external capacitor Voltage sense comparator Thermal shutdown and short circuit protections
Description
The L4949ED-E and L4949EP-E are monolithic integrated 5V voltage regulators with a very low dropout output and additional functions as power- on reset and input voltage sense. They are designed for supplying the microcomputer controlled systems especially in automotive applications. SO-8 SO-20W (12+4+4) Table 1. Device summary
1 Block diagram and pin description
Figure 1. Block diagram Figure 2. Configuration diagram (top view)
Table 2. Pin definitions and functions external voltage divider connected to VS and to GND.
31 V Z
42 C T
the SI voltage becomes lower than an internal voltage.
2 Electrical specifications
2.1 Absolute maximum ratings
Note: The circuit is ESD protected according to MIL-STD-883C.
2.2 Thermal data
Table 3. Absolute maximum ratings Table 4. Thermal data
2.3 Electrical characteristics
Table 5. Electrical characteristics
- With this test we guarantee that with no output current the output voltage will not exceed 5.5V
Table 6. Reset
Table 7. Sense Table 8. Preregulator
3 Application information
Figure 3. Application circuit
3.1 Supply voltage transient
of more than 0.4V/µs can cause a reset signal disturbance. This capacitor (C3 1 µF) reduces also the output noise.
3.2 Functional description
other features and functions when required.
3.3 Voltage regulator
Figure 4. Foldback characteristic of VO dropout operation of the standby regulator is maintained down to 3V input supply voltage. Figure 5. The current consumption of the device (quiescent current) is less than 300 µA.
Figure 5. Output voltage vs input voltage Figure 6. Quiescent current vs supply voltage
3.4 Preregulator
output because the output capability is very small (10 µA). less than 8 V is required (see also application note). feature is not used pin VZ must be left open.
3.5 Reset circuit
The block circuit diagram of the reset circuit is shown in Figure 7. The reset circuit supervises the output voltage. The reset threshold of 4.5 V is defined with the internal reference voltage and standby output divider. The reset pulse delay time tRD, is defined with the charge time of an external capacitor CT: The reaction time of the reset circuit originates from the discharge time limitation of the reset capacitor CT and is proportional to the value of CT. The reaction time of the reset circuit increases the noise immunity. Standby output voltage drops below the reset threshold only a bit longer than the reaction time results in a shorter reset delay time. The nominal reset delay time is generated for standby output voltage drops longer than approximately 50ms. The typical reset output waveforms are shown in Figure 8.
3.6 Sense comparator
The sense comparator compares an input signal with an internal voltage reference of typical 1.23V. The use of an external voltage divider makes this comparator very flexible in the application. It can be used to supervise the input voltage either before or after the protection diode and to give additional informations to the microprocessor like low voltage warnings. tRD CT 2V
4 Package and packing information
4.1 ECOPACK ® packages
specifications, grade definitions and product status are available at: www.st.com. ECOPACK® is an ST trademark.
4.2 SO-8 TP package information
Table 9. SO-8 TP mechanical data
- D and F do not include mold flash or protrusions. Mold flash or protrusions shall not exceed 0.15mm
Figure 9. SO-8 TP package dimensions
4.3 SO-20 TP package information
Table 10. SO-20 TP mechanical data
Figure 10. SO20 TP package dimensions Table 10. SO-20 TP mechanical data (continued)
5 Revision history
Table 11. Document revision history 24-Nov-2009 1 Initial release. 20-Sep-2013 2 Updated disclaimer. 28-Feb-2018 3 Removed tube version for SO-8 package.