L4989 LOW POWER VOLTAGE REGULATOR PRODUCT PREVIEW ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ OPERATING DC SUPPLY VOLTAGE RANGE 5.6V TO 31V VERY LOW QUIESCENT CURRENT WITH WATCHDOG DISABLED PRECISION OUTPUT VOLTAGE (3%) LOW-DROP VOLTAGE (180mV typ at Io = 150mA) RESET CIRCUIT SENSING THE OUTPUT VOLTAGE DOWN TO 1V PROGRAMMABLE RESET DELAY WITH EXTERNAL CAPACITOR WATCHDOG DISABLE INPUT PROGRAMMABLE WATCHDOG TIMER WITH EXTERNAL CAPACITOR THERMAL SHUTDOWN AND SHORT CIRCUIT PROTECTION WIDE TEMPERATURE RANGE (Tj = -40°C TO 150°C) SO8 SO20 ORDERING NUMBERS: L4989D (SO8) L4989 (SO20) BLOCK DIAGRAMt Vs Vo Vi Co Start up 1.25V Voltage Reference gnd 100mV + _ Wi Vcw Ctw WE Vcr watchdog Res Reset Ctr March 2004 This is preliminary information on a new product now in development. Details are subject to change without notice. 1/10 L4989 PIN DESCRIPTION N. (SO8) N. (SO20) NAME FUNCTION 1 1 WEn Watchdog enable input. If high it activates the watchdog operation. 2 4 gnd Ground reference 5,6,15,16 gnd Ground Connected these pins to a heat spreader ground 3 7 Res Reset output. It is pulled down when output voltage goes below Vo_th or frequency at Wi is too low. 4 10 Vcr Reset timing adjust. A capacitor between Vcr pin and gnd, sets the reset delay time (trd) 5 11 Vcw Watchdog timer adjust A capacitor between Vcw pin and gnd, sets the time response of the watchdog monitor. 6 14 Wi Watchdog input. If the frequency at this input pin is too low, the Reset output is activated. 7 17 Vo Voltage regulator output Block to ground with a capacitor >100nF (needed for regulator stability) 8 20 Vs Supply voltage Block to ground directly at IC pin with a ceramic capacitor 2,3,8,9,12, 13,18,19 N. C. not connected PIN CONNECTIONS VEN 1 20 VS N.C. 2 19 N.C. N.C. 3 18 N.C. VEN 1 8 VS GND 2 7 VO RES 3 6 WI GND 4 17 VO VCR 4 5 VCW GND 5 16 GND GND 6 15 GND RES 7 14 WI N.C. 8 13 N.C. N.C. 9 12 N.C. VCR 10 11 WCW D04AT515 SO8 D04AT516 SO20 2/10 L4989 ABSOLUTE MAXIMUM RATINGS Symbol Parameter Value Unit -0.3 to 40 V VVsdc DC supply voltage IVsdc Input current VVo DC output voltage -0.3 to 6 IVo DC output current internally limited VWi Watchdog input voltage -0.3 to VVo + 0.3 V Vod Open drain output voltage (RES) -0.3 to VVo + 0.3 V Iod Open drain output current (RES) internally limited Vcr Reset delay voltage -0.3 to VVo + 0.3 V Vcw Watchdog delay voltage -0.3 to VVo + 0.3 V VWEn Watchdog enable input -0.3 to 40 V Junction temperature -40 to 150 °C ±2 kV Tj VESD internally limited ESD voltage level (HBM-MIL STD 883C) V Note: Maximum ratings are absolute ratings; exceeding any one of these values may cause perma-nent damage to the integrated circuit. THERMAL DATA Symbol Rth-j amb Parameter Thermal Resistance Junction to ambient SO8 SO12+4+4 Unit 130 to 180 50(*) °C/W (*) with 6 sq. cm on board heat sink ELECTRICAL CHARACTERISTICS (Vs = 5.6V to 31V, Tj = -40°C to +150°C unless otherwise specified) Pin Symbol Parameter Test Condition Min. Typ. Max. Unit GENERAL Output voltage Vs=5.6 to 31V Io=1 to 150mA 4.85 5.00 5.15 V Short circuit current (1) Vs=13.5V 160 210 250 mA Output current limitation (1) Vs=13.5V 170 250 290 mA Vline Line regulation voltage Vs=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 Io=150mA 400 mV Vs, Vo SVR Ripple rejection fr = 100 Hz Vs, Vo Iqs_1 Current consumption with watchdog not active Iqs_1 = IVs – Io Vs=13.5V, Io<1mA, WEn low Vo Vo_ref Vo Ishort_13 Vo Ilim Vs, Vo 180 55 dB 69 115 µA 3/10 L4989 Pin Symbol Parameter Vs, Vo Iqs_10 Current consumption with watchdog not active Iqs_10 = IVs – Io Vs, Vo Iqs_50 Vs, Vo Iqs_150 Vs, Vo Typ. Max. Unit Vs=13.5V, Io=10mA, WEn low 127 300 µA Current consumption with watchdog not active Iqs_50 = IVs – Io Vs=13.5V, Io=50mA, WEn low 498 900 µA Current consumption with watchdog not active Iqs_150 = IVs – Io Vs=13.5V, Io=150mA, WEn low 1.40 2 mA Iqn_1 Current consumption with watchdog active Iqn_1 = IVs – Io Vs=13.5V, Io<1mA, WEn high 110 170 µA Vs, Vo Iqn_10 Current consumption with watchdog active Iqn_10 = IVs – Io Vs=13.5V, Io=10mA, WEn high 168 350 µA Vs, Vo Iqn_50 Current consumption with watchdog active Iqn_50 = IVs – Io Vs=13.5V, Io=50mA, WEn high 538 1000 µA Vs, Vo Iqn_150 Current consumption with watchdog active Iqn_150 = IVs – Io Vs=13.5V, Io=150mA, WEn high 1.45 2.00 mA 190 °C Tw Thermal protection temperature Tw_hy Thermal protection temperature hysteresis Test Condition Min. 150 10 °C Note: 1. see fig1 (behavior of output current versus regulated voltage Vo) RESET Pin Symbol Parameter Test condition min Res Vres_l Reset output low voltage Rext = 5kΩ to Vo, Vo > 1V Res IRes_lkg Reset output high leakage current VRes = 5V Res RRes Internal Pull up resistance versus Vo 10 Res Vo_th Reset threshold voltage Vs = 5.6 to 31V Io = 1 to 150mA Vcr Vrhth Reset timing low threshold Vcr Vrlth Vcr typ max Unit 0.4 V 1 µA 20 40 kΩ 6% 8% 10% below Vo_ref Vs =13.5V 10% 13% 16% Vo_ref Reset timing high threshold Vs =13.5V 44% 47% 50% Vo_ref Icr Charge current Vs =13.5V 8 15 30 µA Vcr Idr Discharge current Vs =13.5V 8 15 30 µA Res trr_2 Reset reaction time (2) Vo = Vo_th - 100mV 100 250 700 µs Res trd Reset delay time Vs =13.5V, Ctr =1nF 65 115 165 ms 2. When Vo becomes lower than 4V, the reset reaction time decreases down to 2 s assuring a faster reset condition in this particular case. 4/10 L4989 WATCHDOG Pin Symbol Parameter Test condition min typ max Wi Vih Input high voltage Vs=13.5V Wi Vil Input low voltage Vs=13.5V Wi Vih Input hysteresis Vs=13.5V Wi Rwi Pull down resistor Vs=13.5V 30 100 250 kΩ Vcw Vwhth Low threshold Vs=13.5V 10% 13% 16% Vo_ref Vcw Vwlth High threshold Vs=13.5V 44% 47% 50% Vo_ref Vcw Icwc Charge current Vs=13.5V, Vcw=0.1V 5 10 20 µA Vcw Icwd Discharge current Vs=13.5V, Vcw=2.5V 1.25 2.5 5 µA Vcw Twop Watchdog period Vs=13.5V, Ctw=47nF 20 40 80 ms Res twol Watchdog output low time Vs=13.5V, Ctw=47nF 4 8 16 ms typ max Unit 1 V 3.5 Unit V 1.5 500 V mV WEn Pin Symbol Parameter WEn VWEn_low WEn input low voltage WEn VWEn_high WEn input high voltage WEn VWEn_hyst WEn input hysteresis WEn RWEn Pull down current Test condition min 3 Vs=13.5V V 600 920 1300 mV 1 2.5 5 µA VOLTAGE REGULATOR The voltage regulator uses a p-channel MOS transistor as a regulating element. With this structure a very low dropout voltage at current up to 150mA is obtained. The output voltage is regulated up to transient input supply voltage of 40V. No functional interruption due to over-voltage pulses is generated. The voltage Regulator is always active and not depending on the state of WEn input pin. A short circuit protection to GND is provided. Figure 1. Behavior of output current versus regulated voltage Vo Vo Vo_ref Ishort Ilim Iout 5/10 L4989 The reset circuit monitors the output voltage Vo. If the output voltage stays lower than Vo_th for filter time trr, then Res goes low. If the output voltage Vo becomes lower than 2.0V (typ) than Res goes immediately low. The reset low signal is guaranteed for an output voltage Vo greater than 1V. When the output voltage goes back higher than Vo_th then Res goes high with a delay trd. This delay is obtained by 512 period of an oscillator. The oscillator period is given by: ( V rht h – V rlth ) ⋅ Ctr ( V rht h – V rlth ) ⋅ Ctr Tosc = ------------------------------------------------- + ------------------------------------------------Icr Id trd is given by trd = 512 x Tosc where: Icr = 15µA is an internally generated charge current, Idr = 15µA is an internally generated discharge current, Vrhth=2.35V and Vrlth=0.65V are two typ thresholds, Ctr is an external capacitance. The Reset is always active and not depending on the state of WEn input pin. Figure 2. Reset Time Diagram Wi Vo Vcr Vout_th < trr trr Tosc Vrhth Vrlth trd = 512 Tosc Res Watchdog The watchdog input Wi monitors a connected microcontroller. If pulses are missing, the Reset output Res is set to low. The pulse sequence time can be set within a wide range with the external capacitor Ctw. The watchdog circuit discharges the capacitor Ctw with the con-stant current Icwd. If the lower threshold Vwlth is reached, a watchdog reset is generated. To prevent this reset the microcontroller must generate a positive edge during the discharge of the capacitor before the voltage has reached the threshold Vwlth. In order to calculate the minimum time tdis during which the microcontroller must output the positive edge the fol-lowing equation can be used (Vwhth-Vwlth) x Ctw = Icwd x tdis Every Wi positive edge switches the current source from discharging to charging, the same happens when the lower threshold is reached. When the voltage reaches the upper threshold Vwhth the current switches from charging to discharging. The result is a saw toothwaveform at the watchdog timer capacitor Ctw. The Watchdog operation is active only if WEn input pin is set to logic state high. 6/10 L4989 Figure 3. Watchdog time diagram Wi Twop Vwhth Vcw Vwlth twol Res 7/10 L4989 mm inch DIM. MIN. TYP. MAX. MIN. TYP. MAX. A 1.35 1.75 0.053 0.069 A1 0.10 0.25 0.004 0.010 A2 1.10 1.65 0.043 0.065 B 0.33 0.51 0.013 0.020 C 0.19 0.25 0.007 0.010 D (1) 4.80 5.00 0.189 0.197 E 3.80 4.00 0.15 0.157 e 1.27 0.050 H 5.80 6.20 0.228 0.244 h 0.25 0.50 0.010 0.020 L 0.40 1.27 0.016 0.050 k ddd Note: OUTLINE AND MECHANICAL DATA 0˚ (min.), 8˚ (max.) 0.10 0.004 (1) Dimensions D does not include mold flash, protrusions or gate burrs. Mold flash, potrusions or gate burrs shall not exceed 0.15mm (.006inch) in total (both side). SO-8 0016023 C 8/10 L4989 mm inch DIM. MIN. TYP. MAX. MIN. TYP. MAX. A 2.35 2.65 0.093 0.104 A1 0.10 0.30 0.004 0.012 B 0.33 0.51 0.013 0.200 C 0.23 0.32 0.009 0.013 D (1) 12.60 13.00 0.496 0.512 E 7.40 7.60 0.291 0.299 e 1.27 0.050 H 10.0 10.65 0.394 0.419 h 0.25 0.75 0.010 0.030 L 0.40 1.27 0.016 0.050 k ddd OUTLINE AND MECHANICAL DATA 0˚ (min.), 8˚ (max.) 0.10 0.004 (1) “D” dimension does not include mold flash, protusions or gate burrs. Mold flash, protusions or gate burrs shall not exceed 0.15mm per side. SO20 0016022 D 9/10 L4989 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. 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