L4979D STMICROELECTRONICS | Alldatasheet
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Technical content
1 FEATURES
Figure 2. Block Diagram Figure 1. Packages Table 1. Order Codes
Table 2. Pin Function Figure 3. Pins Connection (Top view) If the frequency at this input pin is too low, the Reset output is activated. Supply capacitor (e.g. 200nF) is needed for regulator stability.
Table 3. Absolute Maximum Ratings Note: 1. Maximum ratings are absolute ratings; exceeding any one of these values may cause permanent damage to the integrated circuit. Table 4. Thermal DatA Table 5. Electrical Characteristcs
Vo Vo_ref Output voltage V s = 5.6 to 31V Io = 1 to 150mA 4.90 5.00 5.10 V Vo Ishort Output short circuit current (1) Vs = 13.5V 150 280 400 mA Vo Ilim Output current limitation (1) Vs = 13.5V 150 320 500 mA Vs, Vo Vline Line regulation voltage V s = 5.6 to 31V Io = 1 to 150mA 25 mV Vo Vload Load regulation voltage Io = 1 to 150mA 25 mV Vs, Vo Vdp Drop voltage I o = 150mA 200 400 mV Vs, Vo SVR Ripple rejection (2) fr = 100 Hz 55 dB RESET R es Vres_l Reset output low voltage Rext = 5kΩ to Vo, Vo > 1V 0.4 V R es Ires_h Reset output high leakage current Vres = 5V 1 µA R es R _p_u Internal Pull up resistance with respect to Vo 12 25 50 k Ω R es Vo_th Reset threshold voltage V s = 5.6 to 31V Io = 1 to 150mA below Vo_ref below Vo_ref 10% below Vo_ref Vcr Vrhth Reset timing high threshold Vs = 13.5V 44% Vo_ref 47% Vo_ref 50% Vo_ref Vcr Vrlth Reset timing low threshold Vs = 13.5V 10% Vo_ref 13% Vo_ref 16% Vo_ref Vcr Icr Charge current V s = 13.5V 8 17 30 µA Vcr Idr Discharge current V s = 13.5V 8 17 30 µA R es trr_2 Reset delay time (3) Vo = V o_th -100mV 100 250 700 µs R es trd Reset pulse delay V s = 13.5V, Ctr = 1nF 65 150 ms WATCHDOG W i Vih Input high voltage V s = 13.5V 3.5 V W i Vil Input low voltage V s = 13.5V 1.5 V W i Vih Input hysteresis V s = 13.5V 300 mV W i Ii Pull down current V s = 13.5V 10 20 µA Vcw Vwhth High threshold V s = 13.5V 2.20 2.35 2.50 V Vcw Vwlth Low threshold V s = 13.5V 0.50 0.65 0.80 V Pin Symbol Parameter Test Condition Min. Typ. Max. Unit Table 5: Electrical Characteristics (continued)
- When Vo becomes lower than 4V, the reset reaction time decreases down to 2µs assuring a faster reset condition in this particular
2 VOLTAGE REGULATOR
voltage is obtained with a pre-trimmed reference voltage. A short circuit protection to GND is provided. Figure 4. Behavior of output current versus regulated voltage Vo (see a.m. Note 1)
3 RESET
guaranteed for an output voltage Vo greater than 1V.
Figure 5. Reset Time Diagram.
4 WATCHDOG
charging to discharging. The result is a saw tooth voltage at the watchdog timer capacitor Ctw. Figure 6. Watchdog time diagram
Figure 7. SO-8 Mechanical Data & Package Dimensions 0.15mm (.006inch) in total (both side).
Figure 8. SO-20 Mechanical Data & Package Dimensions
Table 6. Revision History June 2004 3 Changed the values of the parameter “Reset timing high/low threshold. July 2004 4 Pin Connection SO-20 changed. Changed some textes in the Features and table 2. Changed some values in the tables 3, 4 and 5. Changed some textes in the sections 2, 3 and 4. October 2004 5 Changed from Product Preview to final datasheet.
Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics. The ST logo is a registered trademark of STMicroelectronics. All other names are the property of their respective owners © 2004 STMicroelectronics - All rights reserved STMicroelectronics GROUP OF COMPANIES Australia - Belgium - Brazil - Canada - China - Czech Republic - Finland - France - Germany - Hong Kong - India - Israel - Italy - Japan - Malaysia - Malta - Morocco - Singapore - Spain - Sweden - Switzerland - United Kingdom - United States L4979MD - L4979D