L4981A L4981B POWER FACTOR CORRECTOR CONTROL BOOST PWM UP TO 0.99P.F. LIMIT LINE CURRENT DISTORTION TO < 5% UNIVERSAL INPUT MAINS FEED FORWARD LINE AND LOAD REGULATION AVERAGE CURRENT MODE PWM FOR MINIMUM NOISE SENSITIVITY HIGH CURRENT BIPOLAR AND DMOS TOTEM POLE OUTPUT LOW START-UP CURRENT (0.3mA TYP.) UNDER VOLTAGE LOCKOUT WITH HYSTERESIS AND PROGRAMMABLE TURN ON THRESHOLD OVERVOLTAGE, OVERCURRENT PROTECTION PRECISE 2% ON CHIP REFERENCE EXTERNALLY AVAILABLE SOFT START DESCRIPTION The L4981 I.C. provides the necessary features to achieve a very high power factor up to 0.99. Realized in BCD 60II technology this power factor corrector (PFC) pre-regulator contains all the con- MULTIPOWER BCD TECHNOLOGY DIP20 SO20 ORDERING NUMBERS: L4981X (DIP20) L4981XD (SO20) trol functions for designing a high efficiency-mode power supply with sinusoidal line current consumption. The L4981 can be easily used in systems with mains voltages between 85V to 265V without any line switch. This new PFC offers the possibility to work at fixed frequency (L4981A) or modulated frequency (L4981B) optimizing the size of the in- BLOCK DIAGRAM September 1998 1/17 L4981A - L4981B put filter; both the operating frequency modes working with an average current mode PWM controller, maintaining sinusoidal line current without slope compensation. Besides power MOSFET gate driver, precise voltage reference (externally available), error amplifier, undervoltage lockout, current sense and the soft start are included. To limit the number of the external components, the device integrates protections as overvoltage and overcurrent. The overcurrent level can be programmed using a simple resistor for L4981A. For a better precision and for L4981B an external divider must be used. ABSOLUTE MAXIMUM RATINGS Symbol Pin VCC 19 IGDRV 20 Parameter Value Unit selflimit V 2 1.5 Α A Gate driv. output voltage t = 0.1µs -1 V Voltages at pins 3, 14, 7, 6, 12, 15 -0.3 to 9 V Supply Voltage (ICC ≤50mA) (*) Gate driv. output peak current (t = 1µs) . VGDRV SINK SOURCE VVA-OUT 13 Error Amplifier Voltage IAC 4 AC Input Current VCA-OUT 5 Current Amplifier Volt. (Isource = -20mA; Isink = 20mA) 17 -0.3 to 8.5 V 5 mA Voltages at pin 8, 9 VROSC 11, 18 -0.5 to 7 V -0.3 to 8.5 V Voltage at pin 17 -0.3 to 3 V Voltage at pin 11, 18 -0.3 to 7 V ICOSC 18 Input Sink Current 15 mA IFREQ-MOD 16 Frequency Modulation Sink Current (L4981B) 5 mA V SYNC 16 Sync. Voltage (L4981A) -0.3 to 7 V V IPK 2 Voltage at pin 2 Voltage at Pin 2 t = 1µs -0.3 to 5.5 -2 V V W Ptot Power Dissipation at Tamb = 70°C (DIP20) 1 Power Dissipation at Tamb = 70°C (SO20) 0.6 W Top Operating Ambient Temperature -40 to 125 °C Tstg StorageTemperature -55 to 150 °C (*) Maximum package power dissipation limits must be observed. PIN CONNECTIONS (Top views) L4981A 2/17 L4981B L4981A - L4981B THERMAL DATA Symbol Parameter Rth j-amb Thermal Resistance Junction-ambient DIP 20 SO 20 Unit 80 120 °C/W PIN FUNCTIONS N. Name 1 P-GND 2 IPK Description Power ground. L4981A peak current limiting. A current limitation is obtained using a single resistor connected between Pin 2 and the sense resistor. To have a better precision another resistor between Pin 2 and a reference voltage (Pin 11) must be added. L4981B peak current limiting. A precise current limitation is obtained using two external resistor only. These resistors must be connected between the sense resistor, Pin 2 and the reference voltage. 3 OVP Overvoltage protection. At this input are compared an internal precise 5.1V (typ) voltage reference with a sample of the boost output voltage obtained via a resistive voltage divider in order to limit the maximum output peak voltage. 4 IAC Input for the AC current. An input current proportional to the rectified mains voltage generates, via a multiplier, the current reference for the current amplifier. 5 CA-OUT 6 LFF Load feedforward; this voltage input pin allows to modify the multiplier output current proportionally to the load, in order to give a faster response versus load transient. The best control is obtained working between 1.5V and 5.3V. If this function is not used, connect this pin to the voltage reference (pin = 11). 7 VRMS Input for proportional RMS line voltage. the VRMS input compesates the line voltage changes. Connecting a low pass filter between the rectified line and the pin 7, a DC voltage proportional to the input line RMS voltage is obtained. The best control is reached using input voltage between 1.5V and 5.5V. If this function is not used connect this pin to the voltage reference (pin = 11). 8 MULT-OUT Multiplier output. This pin common to the multiplier output and the current amplifier N.I. input is an high impedence input like ISENSE. The MULT-OUT pin must be taken not below -0.5V. Current amplifier output. An external RC network determinates the loop gain. 9 ISENSE Current amplifier inverting input. Care must be taken to avoid this pin goes down -0.5V. 10 S-GND Signal ground. 11 VREF 12 SS 13 VA-OUT Error amplifier output, an RC network fixes the voltage loop gain characteristics. 14 VFEED Voltage error amplifier inverting input. This feedback input is connected via a voltage divider to the boost output voltage. 15 P-UVLO Programmable under voltage lock out threshold input. A voltage divider between supply voltage and GND can be connected in order to program the turn on threshold. 16 SYNC (L4981A) This synchronization input/output pin is CMOS logic compatible. Operating as SYNC in, a rectangular wave must be applied at this pin. Opearting as SYNC out, a rectangular clock pulse train is available to synchronize other devices. FREQ-MOD (L4981B) Output reference voltage (typ = 5.1V).Voltage refence at ± 2% of accuracy externally available, it’s internally current limited and can deliver an output current up to 10mA. A capacitor connected to ground defines the soft start time. An internal current generator delivering 100µA (typ) charges the external capacitor defining the soft start time constant. An internal MOS discharge, the external soft start capacitor both in overvoltage and UVLO conditions. Frequency modulation current input. An external resistor must be connected between pin 16 and the rectified line voltage in order to modulate the oscillator frequency. Connecting pin 16 to ground a fixed frequency imposed by ROSC and COSC is obtained. 17 R OSC An external resistor connected to ground fixes the constant charging current of COSC. 18 C OSC An external capacitor connected to GND fixes the switching frequency. 19 VCC Supply input voltage. 20 GDRV Output gate driver. Bipolar and DMOS transistors totem pole output stage can deliver peak current in excess 1A useful to drive MOSFET or IGBT power stages. 3/17 L4981A - L4981B ELECTRICAL CHARACTERISTICS (Unless otherwise specified VCC = 18V, COSC = 1nF, ROSC = 24KΩ, CSS = 1µF, VCA-OUT = 3.5V, VISENSE = 0V, VLFF = VREF, IAC = 100µA, VRMS = 1V, VFEED = GND, VIPK = 1V, V OVP = 1V, TJ = 25°C Symbol Prameter Test Condition Min. Typ. Max. Unit ±8 mV -500 -50 500 nA 70 100 5.5 6.5 7.5 V 0.4 1 V ERROR AMPLIFIER SECTION VIO Input Offset Voltage –25°C < TJ < 85°C IIB Input Bias Current VFEED = 0V Open Loop Gain dB V13H Output High voltage VFEED = 4.7V IVA-OUT = -0.5mA V13L Output Low Voltage VFEED = 5.5V IVA-OUT = 0.5mA -I13 Output Source Current VFEED = 4.7V; VVA-OUT = 3.5V 2 10 mA I13 Output Sink Current VFEED = 5.5V; VVA-OUT = 3.5V 4 20 mA REFERENCE SECTION Vref Reference Output Voltage –25°C < TJ < 85°C 4.97 5.1 5.23 V Tj = 25°C Iref = 0 5.01 5.1 5.19 V ∆Vref Load Regulation 1mA ≤ Iref ≤ 10mA –25°C < TJ < 85°C 3 15 mV ∆Vref Line Regulation 12V ≤ VCC ≤ 19V –25°C < TJ < 85°C 3 10 mV Iref sc Short Circuit Current Vref = 0V 20 30 50 mA Initial Accuracy Tj = 25°C 85 100 115 KHz Frequency Stability 12V ≤ VCC ≤ 19V –25°C < TJ < 85°C 80 100 120 KHz OSCILLATOR SECTION fosc Vsvp Ramp Valley to Peak I18C Charge Current VCOSC = 3.5V I18D Discharge Current VCOSC = 3.5V V 18 Ramp Valley Voltage 4.7 5 5.3 V 0.45 0.55 0.65 mA 11.5 0.9 1.15 mA 1.4 V SYNC SECTION (Only for L4981A) tW Output Pulse Width 50% Amplitude 0.3 0.8 µs I16 Sink Current with Low Output Voltage VSYNC = 0.4V VCOSC = 0V 0.4 0.8 mA -I16 Source Current with High Output Voltage VSYNC = 4.5V VCOSC = 6.7V 1 6 mA V16L Low Input Voltage V16H High Input Voltage 0.9 Pulse for Synchronization td FREQUENCY MODULATION FUNCTION (Only for L4981B) V 3.5 V 800 ns f18max Maximum Oscillation Frequency VFREQ-MOD = 0V (Pin 16) Ifreq = 0 f18min Minimum Oscillator Frequency IFREQ-MOD = 360µA (Pin 16) VVRMS = 4V (Pin 7) 85 100 74 115 KHz KHz IFREQ-MOD = 180µA (Pin 16) VVRMS = 2V (Pin 7) 76 KHz SOFT START SECTION 4/17 ISS Soft Start Source Current VSS = 3V V12sat Output Saturation Voltage V3 = 6V, ISS = 2mA 60 100 140 µA 0.1 0.25 V L4981A - L4981B ELECTRICAL CHARACTERISTICS (continued) Symbol Parameter Test Condition Min. Typ. Max. Unit 19.5 V 5.1 Vref +20mV V SUPPLY VOLTAGE VCC Operating Supply Voltage OVER VOLTAGE PROTECTION COMPARATOR Vthr V3Hys Rising Threshold Voltage Vref -20mV Hysteresis I3 Input Bias Current td Propagation delay to output 180 VOVP = Vthr +100mV 250 320 mV 0.05 1 µA 1 2 µs OVER CURRENT PROTECTION COMPARATOR V th Propagation delay to Output VOCP = Vthr -0.2V Iipk Current Source Generator VIPK = -0.1V only for L4981A VIPK = -0.1V only for L4981B Leakage Current IL CURRENT AMPLIFIER SECTION Voffset ±30 mV 0.4 0.9 µs 85 105 µA 5 µA ±2 mV Threshold Voltage td Input Offset Voltage 65 VMULT OUT = VSENSE = 3.5V Input Bias Current VSENSE = 0V -500 50 Open Loop Gain 1.1V ≤ VCA OUT ≤ 6V 70 100 dB SVR Supply Voltage Rejection 12V ≤ VCC ≤ 19V VMULT OUT = 3.5V VSENSE = 3.5V 68 90 dB V5H Output High Voltage VMULT OUT = 200mV ICA OUT = -0.5mA, VIAC = 0V 6.2 V 5L Output Low Voltage VMULT OUT = -200mV ICA OUT = 0.5mA, VIAC = 0V -I5 Output Source Current I5 Output Sink Current VMULT OUT = 200mV, VIAC = 0V, VCA-OUT = 3.5V I9bias 500 nA V 0.9 V 2 10 mA 2 10 mA 11.5 12.5 OUTPUT SECTION V20L Output Voltage Low ISINK = 250mA V20H Output Voltage High ISOURCE = 250mA VCC = 15V tr Output Voltage Rise Time COUT = 1nF 50 150 ns tf Output Voltage Fall Time COUT = 1nF 30 100 ns Voltage Clamp ISOURCE = 0mA 16 19 V 0.3 0.5 mA 8 12 mA VGDRV 0.5 13 0.8 V V TOTAL STANDBY CURRENT SECTION I19start Supply Current before start up VCC = 14V I19on Supply Current after turn on VIAC = 0V, VCOSC = 0, Pin17 = Open Operating Supply Current Pin20 = 1nF Zener Voltage (*) I19 VCC 12 16 mA 20 25 30 V UNDER VOLTAGE LOCKOUT SECTION Vth ON Turn on Threshold 14.5 15.5 16.5 V Vth OFF Turn off Threshold 9 10 11 V 10.6 12 13.4 V V6 = 1.6V 70 140 µA V6 = 5.3V 200 300 µA 5.3 V Programmable Turn-on Threshold Pin 15 to VCC = 220K Pin15 to GND = 33K LOAD FEED FORWARD ILFF VI Bias Current Input Voltage Range 1.6 (*) Maximum package power dissipation limits must be observed. 5/17 L4981A - L4981B ELECTRICAL CHARACTERISTICS (continued) Symbol Prameter Test Condition Min. Typ. Max. Unit VVA-OUT = 4V, VRMS = 2V, VMULTOUT = 0, VLFF = 5.1V IAC = 50µA, COSC = 0V 20 35 52 µA VVA-OUT = 4V, VRMS = 2V, VMULTOUT = 0, VLFF = 5.1V IAC = 200µA, COSC = 0V 100 135 170 µA VVA-OUT = 2V, VRMS = 2V, VMULTOUT = 0, VLFF = 5.1V IAC = 100µA, COSC = 0V 10 20 30 µA VVA-OUT = 2V, VRMS = 4V, VMULTOUT = 0, VLFF = 5.1V IAC = 100µA, COSC = 0V 2 5.5 11 µA VVA-OUT = 4V, VRMS = 4V, VMULTOUT = 0, VLFF = 5.1V IAC = 100µA, COSC = 0V 10 22 34 µA VVA-OUT = 4V, VRMS = 2V, VMULTOUT = 0, VLFF = 2.5V COSC = 0V, IAC = 200µA 20 37 54 µA VVA-OUT = 4V, VRMS = 4V VMULTOUT = 0, VLFF = 5.1V IAC = 200µA, COSC = 0V 20 39 54 µA VVA-OUT = 2V, VRMS = 4V, VMULTOUT = 0, VLFF = 5.1V IAC = 0, COSC = 0V -2 0 2 µA MULTIPLIER SECTION Multipler Output Current K Multiplier Gain IMULT−OUT = K ⋅ IAC if VLFF = VREF; 0.37 (VVA−OUT − 1.28) ⋅ (0.8 ⋅ VLFF − 1.28) IMULT−OUT = IAC (VVRMS)2 (VVA−OUT − 1.28) 2 (VVRMS) ⋅ K1 where: K1 = 1V Figure 1: MULTI-OUT vs. IAC (VRMS = 1.7V; VLFFD = 5.1V) 6/17 Figure 2: MULTI-OUT vs. IAC (VRMS = 2.2V; VLFFD = 5.1V) L4981A - L4981B Figure 3: MULTI-OUT vs. IAC (VRMS = 4.4V; VLFFD = 5.1V) Figure 4: MULTI-OUT vs. IAC (VRMS = 5.3V; VLFFD = 5.1V) Figure 5: MULTI-OUT vs. IAC (VRMS = 1.7V; VLFFD = 2.5V) Figure 6: MULTI-OUT vs. IAC (VRMS = 2.2V; VLFFD = 2.5V) Figure 7: MULTI-OUT vs. IAC (VRMS = 4.4V; VLFFD = 2.5V) Figure 8: MULTI-OUT vs. IAC (VRMS = 5.3V; VLFFD = 2.5V) 7/17 L4981A - L4981B Figure 9A: L4981A Power Factor Corrector (200W) T C7 R14 FUSE BRIDGE C12 R15 D4 D3 C5 R7 C8 + Vo=400V D1 R6 R1 R9 C9 R8 R12 Vi 7 4 19 1 13 85VAC-265VAC 14 3 15 C1 L4981A 16 2 20 8 5 9 18 10 17 R13 R11 R3 MOS 6 12 11 D5 R21 R5 C2 C11 D2 R17 R2 R10 C3 R4 C4 R16 C6 C10 RS D93IN029B PART LIST RS 0.07(3 x .22) 1/2W 5% C1 470nF 400V R1 820kΩ 1/4W 1% C2 100µF 450V R2 10kΩ 1/4W 1% C3 2.2nF R3 1.8kΩ 1/4W 5% C4 1nF R4 1.8kΩ 1/4W 5% C5 100µF R5 18kΩ 1/4W 5% C6 1µF 16V R6 1.2MΩ 1/4W 5% C7 220nF 63V R7 360kΩ 1/4W 5% C8 220nF 63V R8 33kΩ 1/4W 5% C9 330nF R9 1.8MΩ 1/4W 1% C10 1µF 16V R10 21kΩ 1/4W 1% C11 270pF 400V R11 402Ω 1/4W 1% C12 8.2nF 100V R12 120kΩ 1/4W 5% D1 STTA506D R13 27Ω 1/4W 5% D2, D3 1N4148 R14 1MΩ 1/4W 1% D4 18V R15 120kΩ 1/2W 5% D5 BYT11-600 R16 30kΩ 1/4W 5% MOS STH/STW15NA50 R17 1.8kΩ 4W 1% R21 5.1kΩ 1/4W 1% FUSE = 4A/250V BRIDGE = 4 x P600M T= primary: 88 turns of 12 x 32 AWG (0.2mm) secondary: 9 turns of # 27AWG (0.15mm) core: B1ET3411A THOMSON - CSF gap: 1,6mm for a total primary inductance of 0.9mH 8/17 fSW = 80kHz PO = 200W VOUT = 400V Irms max = 2.53A VOVP = 442V IPK max = 6.2A 25V 1/2W L4981A - L4981B Figure 9B: L4981B Power Factor Corrector (200W) T R22 + Vo=400V D1 R6 C7 R14 C12 R15 D4 D3 C5 R1 R7 C8 FUSE BRIDGE R9 C9 R8 R12 Vi 7 4 19 1 13 14 85VAC-265VAC 3 C1 C2 C11 D2 15 L4981B 16 20 R13 MOS 6 2 8 5 9 18 10 17 12 11 D5 R21 R5 R11 R3 R17 R2 R10 C3 R4 C4 R16 C6 C10 RS D95IN220 PART LIST RS R1 0.07(3 x .22) 1/2W 5% C1 470nF 400V 820kΩ 1/4W 1% C2 100µF 450V R2 10kΩ 1.8kΩ 1/4W 1/4W 1% 5% C3 2.2nF R3 C4 1.1nF R4 R5 1.8kΩ 18kΩ 1/4W 1/4W 5% 5% C5 100µF C6 1µF 16V R6 R7 1.2MΩ 1/4W 5% C7 220nF 63V 360kΩ 1/4W 5% C8 220nF 63V R8 1/4W 1/4W 1/4W 5% 1% 1% C9 330nF R9 R10 33kΩ 1.8MΩ 21kΩ C10 1µF 16V C11 270pF 400V R11 R12 402Ω 1/4W 1% C12 8.2nF 100V 120kΩ 1/4W 5% D1 STTA506D 27Ω 1MΩ 1/4W 1/4W 5% 1% D2, D3 1N4148 R14 D4 18V R15 R16 120kΩ 24kΩ 1/2W 1/4W 5% 5% R17 R21 1.8kΩ 4W 1% 5.1kΩ 1/4W 1% R13 R22 1.1MΩ 1/4W BRIDGE = 4 x P600M D5 BYT11-600 MOS STH/STW15NA50 25V 1/2W FUSE = 4A/250V 1% T= primary: 88 turns of 12 x 32 AWG (0.2mm) secondary: 9 turns of # 27AWG (0.15mm) core: B1ET3411A THOMSON - CSF gap: 1,6mm for a total primary inductance of 0.9mH fSW = 80 to 92kHz PO = 200W VOUT = 400V Irms max = 2.53A VOVP = 442V IPK max = 6.2A 9/17 L4981A - L4981B Figure 10: Reference Voltage vs. Source Reference Current Figure 11: Reference Voltage vs. Supply Voltage Figure 12: Reference Voltage vs. Junction Temperature Figure 13: Switching Frequency vs. Junction Temperature Figure 14: Gate Driver Rise and Fall Time Figure 15: Operating Supply Current vs. Supply Voltage 10/17 L4981A - L4981B Figure 16: Programmable Under Voltage Lockout Thresholds Figure 17: Modulation Frequency Normalized in an Half Cycle of the Mains Voltage 1 fsw Vl 1 0.8 0.8 0.4 0.4 0.2 0.2 R22 = R23 ⋅ 6.8 0 45 0 R23 (Kohm) 90 0 135 180 Electrical degrees Table 1: Programmable Under Voltage Lockout Thresholds. VCC ON VCC OFF R22 R23 11V 10V 82kΩ 12kΩ 12V 10.1V 220kΩ 33kΩ 13V 10.5V 430kΩ 62kΩ 14V 10.8V 909kΩ 133kΩ 14.5V 10.9V 1.36MΩ 200kΩ 15V 11V 2.7MΩ 390kΩ Figure 18: Oscillator Diagram 11/17 L4981A - L4981B Figure 19: 200W Evaluation Board Circuit. T= primary: 75 turns of litz wire 20 x 32 AWG (0.2mm) secondary: 8 turns of # 27AWG (0.15mm) core: B1ET3411A THOMSON - CSF gap: 1.4mm for a total primary inductance of 0.7mH fsw = 100kHz; VO = 400V; PO = 200W NOTE: Start Up Circuit Usually the VCC capacitor (C11 in fig. 19) can be charged by a resistor drawing current from the rectified mains. In the evaluation board instead the start up circuit composed by (Q2+R19+R15+Dz) has been designed to perform a fast and effective supply in all the conditions. Once that the L4981A/B has started, the reference 12/17 voltage available at pin 6 by R20 and Q3, ensures Q2 to be turned off. Programmable Under voltage Lockout The PCB allows to insert a couple of resistor (R22, R23) to modify the threshold input voltage. Please refer to fig. 16 and table1. L4981A - L4981B Figure 20: P.C. Board and Component Layout of Evaluation Board Circuit (1:1 scale). 13/17 L4981A - L4981B a NTC resistor can be used. The PFC demoboard performances has been evaluated testing the following parameters: PF (power factor), A-THD (percentage of current total harmonic distortion), H3..H9 (percentage of current’s nth harmonic amplitude), ∆Vo (output voltage ripple), Vo (output voltage), η (efficiency). The test configuration, equipments and results are: The evaluation board has been designed using: a faster not dissipative start-up circuit, a diode (D2) to speed-up the MOS start-off time and (even if a single resistor can be used) an external divider to improve the precision of the overcurrent threshold. Further there is a possibility to change the input threshold voltage using an external divider (R23 and R22) and if an inrush current problem arises AC POWER SOURCE LARCET /3KW PM1200 AC POWER ANALYSER PFC L4981 DEMO EMI FILTER LOAD D94IN057 A-THD H3 H5 H7 H9 VO ∆VO PO η (%) (%) (%) (%) (%) (V) (V) (W) (%) 0.999 2.94 1.98 0.61 0.55 0.70 390 8 200 90.2 220 0.999 1.79 1.40 0.40 0.31 0.28 392 8 201 91.6 60 218 0.999 1.71 1.16 0.40 0.35 0.31 394 8 202 92.8 50 217 0.999 1.88 1.52 0.65 0.40 0.34 396 8 203 93.8 220 50 217 0.997 2.25 1.68 0.83 0.57 0.48 398 8 204 94.2 260 50 216 0.995 3.30 1.84 1.30 0.39 0.73 400 8 205 95.2 Vi f Pi (Vrms) (Hz) (W) 88 60 222 110 60 132 180 PF EMI/RFI FILTER The harmonic content measurement has been done using an EMI/RFI filter interposed between T1 LINE the AC source and the demoboard under test, while the efficiency has been calculated without the filter contribution. T2 C1 PFC C EARTH D94IN052 where: T1 = 1mH T2 = 27mH 14/17 C1 = 0.33µF, 630V C2 = 2.2nF, 630V L4981A - L4981B SO20 PACKAGE MECHANICAL DATA mm DIM. MIN. inch TYP. MAX. MIN. TYP. MAX. A 2.35 2.65 0.093 0.104 A1 0.1 0.3 0.004 0.012 B 0.33 0.51 0.013 0.020 C 0.23 0.32 0.009 0.013 D 12.6 13 0.496 0.512 E 7.4 7.6 0.291 0.299 e 1.27 0.050 H 10 10.65 0.394 0.419 h 0.25 0.75 0.010 0.030 L 0.4 1.27 0.016 0.050 K 0 (min.)8 (max.) L h x 45° A B e A1 K C H D 20 11 E 1 10 SO20MEC 15/17 L4981A - L4981B DIP20 PACKAGE MECHANICAL DATA mm DIM. MIN. a1 0.254 B 1.39 TYP. MAX. MIN. TYP. MAX. 0.010 1.65 0.055 0.065 b 0.45 0.018 b1 0.25 0.010 D 25.4 1.000 E 8.5 0.335 e 2.54 0.100 e3 22.86 0.900 F 7.1 0.280 I 3.93 0.155 L Z 16/17 inch 3.3 0.130 1.34 0.053 L4981A - L4981B 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. Specification 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 1998 STMicroelectronics – Printed in Italy – All Rights Reserved STMicroelectronics GROUP OF COMPANIES Australia - Brazil - Canada - China - France - Germany - Italy - Japan - Korea - Malaysia - Malta - Mexico - Morocco - The Netherlands Singapore - Spain - Sweden - Switzerland - Taiwan - Thailand - United Kingdom - U.S.A. 17/17