IP1842 SERIES IP1843 SERIES TOP VIEW COMP 1 8 VREF V FB 2 7 VCC I SENSE 3 6 OUTPUT R T /C T 4 5 GROUND CURRENT MODE REGULATING PULSE WIDTH MODULATORS J Package – 8 Pin Ceramic DIP N Package – 8 Pin Plastic DIP D-8 Package – 8 Pin Plastic (150) SOIC FEATURES • • • • • Guaranteed ±1% reference voltage tolerance Guaranteed ±10% frequency tolerance Low start–up current (<500 mA) Under voltage lockout with hysteresis Output state completely defined for all supply and input conditions • Interchangeable with UC1842 and UC1843 series for improved operation • 500kHz operation TOP VIEW COMP 1 14 VREF N/C 2 13 N/C V FB 3 12 VCC N/C 4 11 VC I SENSE 5 10 OUTPUT 6 9 GROUND R T /C T 7 8 POWER GROUND N/C D-14 Package – 14 Pin Plastic (150) SOIC Order Information Part Number IP1842 IP2842 IP3842 IP1843 IP2843 IP3843 J–Pack 8 Pin ✔ ✔ ✔ ✔ ✔ ✔ N–Pack 8 Pin ✔ ✔ ✔ ✔ D–8 8 Pin ✔ ✔ ✔ ✔ D–14 14 Pin ✔ ✔ ✔ ✔ Temp. Range -55 to +125°C -25 to +85°C 0 to +70°C -55 to +125°C -25 to +85°C 0 to +70°C Note: To order, add the package identifier to the part number. eg. IP1842J IP3843D-14 ABSOLUTE MAXIMUM RATINGS (Tcase = 25°C unless otherwise stated) VCC Supply Voltage IO Output Current Output Energy Analog Inputs Error Amp Output Sink Current Power Dissipation Derate @ Tamb > 50°C Power Dissipation Derate @ Tcase > 25°C Storage Temperature Range Lead Temperature PD PD TSTG TL Semelab plc. (low impedance source) (ICC < 30mA) (capacitive load) (pins 2 and 3) Tamb = 25°C Tcase = 25°C (soldering, 10 seconds) Telephone +44(0)1455 556565. Fax +44(0)1455 552612. E-mail: [email protected] Website: http://www.semelab.co.uk +30V Self limiting ±1A 5mJ –0.3V to +VCC 10mA 1W 10mW/°C 2W 24mW/°C –65 to 150°C +300°C Prelim.3/00 IP1842 SERIES IP1843 SERIES DESCRIPTION The IP1842 and IP1843 series of switching regulator control circuits contain all the functions necessary to implement off–line, current mode switching regulators, using a minimum number of external parts. Functions included are voltage reference, error amplifier, current sense comparator, oscillator, totem pole output driver and under-voltage lockout circuitry. Although pin compatible with the UC1842 and 1843 series, SEMELAB has incorporated several improvements in the IP1842 and IP1843 series allowing tighter and more complete specification of electrical performance. BLOCK DIAGRAM VCC 7/12 UNDER–VOLTAGE LOCKOUT 34V ENABLE G ND REFERENCE 5V REGULATOR 5/9 16V (8.4V) 6V (0.5V) 8/14 VREF INTERNAL BIAS REG 2.5V S VREF STATUS LATCH 7/11 R VC 3.6V R T /CT 6/10 4/7 OSCILLATOR ERROR AMP V FB 2/3 C OMP 1/1 I SENSE 3/5 S 2R R R 1V 5/8 PWM LATCH OUTPUT POW ER GROUND CURRENT SENSE COMPARATOR Values in brackets are for IP1843 series. PIN NUMBERS 1st Number – N, J and 8 Pin D Packages 2nd Num ber – 14 Pin D Package. RECOMMENDED OPERATING CONDITIONS VCC Supply Voltage 1 IO Output Current Analog Inputs £ 30V 0 to ±200mA (pins 2 and 3) –0.3V to 3V Error Amp Output Sink Current Operating Ambient Temperature Range 0 to 2mA IP1842 , IP1843 IP2842 , IP2843 IP3842 , IP3843 –55 to 125°C –25 to 85°C 0 to 70°C Notes: 1. Lower limit set by under voltage lockout specification. Semelab plc. Telephone +44(0)1455 556565. Fax +44(0)1455 552612. E-mail: [email protected] Website: http://www.semelab.co.uk Prelim.3/00 IP1842 SERIES IP1843 SERIES ELECTRICAL CHARACTERISTICS (Over Full Operating Temperature Range unless otherwise stated) Parameter Test Conditions IP1842/IP1843 IP2842/IP2843 Min. Typ. Max. Min. IP3842 IP3843 Typ. 4.95 4.90 5.00 5.10 Max. Units REFERENCE SECTION 5.00 5.05 VCC = 12V to 25V 6 20 6 20 IO = 1mA to 20mA 6 25 6 25 0.2 0.4 0.2 0.4 Output Voltage IO = 1mA Input Regulation Output Regulation TJ = 25°C Temperature Stability Total Output Variation Line, Load, Temp Output Noise Voltage f = 10Hz to 10kHz Long Term Stability TJ = 125°C @ 1000Hrs Output Short Circuit Current 4.90 TJ = 25°C 5.10 4.82 50 50 VREF = 0 5.18 5 25 30 80 160 47 52 57 1 V mV mV °C V m V 5 25 mV 30 80 160 mA 47 52 57 kHz 0.2 1 % OSCILLATOR SECTION Frequency TJ = 25°C Voltage stability VCC = 12V to 25V 0.2 Temperature Stability D TA = Min to Max 5 5 % Amplitude VPIN4 Peak to Peak 1.7 1.7 V TJ = 25°C 8.3 8.3 mA 8 8 % Discharge Current TA = Min to Max D ERROR AMP SECTION Input Voltage VPIN1 = 2.5V 2.45 Input Bias Current Open Loop Voltage Gain VO = 2V to 4V Unity Gain Bandwidth Supply Voltage VCC = 12V to 25V Rejection 2.50 2.55 –0.3 –1 2.42 2.50 2.58 –0.3 –2 V m A 65 90 65 90 dB 0.7 1 0.7 1 MHz 60 70 60 70 dB Output Sink Current VPIN2 = 2.7V VPIN1 = 1.1V 2 6 2 6 Output Source Current VPIN2 = 2.3V VPIN1 = 4.6V –0.5 –0.8 –0.5 –0.8 VOUT High VPIN2 = 2.3V RL = 15kW 4.6 4.8 4.6 4.8 VOUT Low VPIN2 = 2.7V RL = 15kW 0.7 1.1 0.7 mA 1.1 V NOTES 1. Test Conditions unless otherwise stated: VCC = 15V* , RT = 10kW , CT = 3.3nF , f = 52kHz. *Adjust VCC above start threshold before setting at required level. All specifications apply over the full operating temperature range unless otherwise stated. (See Ordering Information for further details). Semelab plc. Telephone +44(0)1455 556565. Fax +44(0)1455 552612. E-mail: [email protected] Website: http://www.semelab.co.uk Prelim.3/00 IP1842 SERIES IP1843 SERIES ELECTRICAL CHARACTERISTICS (Over Full Operating Temperature Range unless otherwise stated) Parameter Test Conditions IP1842/IP1843 IP2842/IP2843 Min. Typ. Max. Min. IP3842 IP3843 Typ. 2.85 3 3.15 2.85 3 3.15 V/V 0.9 1 1.1 0.9 1 1.1 V 60 70 60 70 Max. Units CURRENT SENSE SECTION Gain See Notes 2,3 Maximum Input Signal VPIN1 = 4.6V Supply Voltage (Note 2) VC = 12V to 25V Rejection dB Input Bias Current –2 –10 –2 –10 m Delay to Output 200 400 200 400 ns ISINK = 20mA 0.1 0.4 0.1 0.4 ISINK = 200mA 1.5 2.2 1.5 2.2 A OUTPUT SECTION Output Low Level Output High Level ISOURCE = 20mA 13 13.5 13 13.5 ISOURCE = 200mA 12 13.5 12 13.5 V V Rise Time CL = 1nF TJ = 25°C 50 150 50 150 Fall Time CL = 1nF TJ = 25°C 50 150 50 150 UVLO Saturation VCC = 6V IL = 1mA 0.7 1.1 0.7 1.1 ns V UNDER–VOLTAGE LOCKOUT SECTION Upper Threshold 1842 Series 15 16 17 14.5 16 17.5 (VCC) 1843 Series 7.8 8.4 9 7.8 8.4 9 Lower Threshold 1842 Series 9 10 11 8.5 10 11.5 (VCC) 1843 Series 7 7.6 8.2 7 7.6 8.2 0.3 0.5 0.3 0.5 V V TOTAL STANDBY CURRENT Start–up Current Operating Supply VPIN2 = 0V 1842 Series 11 15 11 15 Current VPIN3 = 0V 1843 Series 14 17 14 17 VCC Zener Voltage ICC = 25mA 34 40 34 40 30 30 mA mA V NOTES 1. Test Conditions unless otherwise stated: VCC = 15V* , RT = 10kW , CT = 3.3nF , f = 52kHz. *Adjust VCC above start threshold before setting at required level. 2. Parameter measured at trip point of latch with VPIN2 = 0V 3. Gain defined as: A= VPIN1 VPIN3 D D All specifications apply over the full operating temperature range unless otherwise stated. (See Ordering Information for further details). Semelab plc. Telephone +44(0)1455 556565. Fax +44(0)1455 552612. E-mail: [email protected] Website: http://www.semelab.co.uk 0 £ VPIN3 £ 0.8 Prelim.3/00 IP1842 SERIES IP1843 SERIES APPLICATIONS INFORMATION Oscillator Waveforms and Maximum Duty Cycle COMP 1 8 VREF V FB 2 7 VCC I SENSE 3 6 OUTPUT R T /C T 4 5 GROUND Oscillator timing capacitor C T is charged by V REF tc » 0.55 RTCT through RT and discharged by an internal current source. .0063 RT – 2.3 During the discharge time, the internal clock signal td » RTCT Rn .0063 – 4 blanks the output to the low state. Selection of RT and 1 CT therefore determines both oscillator frequency and Resultant frequency f = (tc + td) maximum duty cycle. Charge and discharge times are determined by the formulae: ( ) For RT > 5kW, Resultant frequency f » 1.8 (RTCT) Open–Loop Laboratory Test Fixture COMP 1 14 VREF N/C 2 13 N/C V FB 3 12 VCC N/C 4 11 VC I SENSE 5 10 OUTPUT 6 9 GROUND R T /C T 7 8 POWER GROUND N/C High peak current associated with capacitive loads necessitate careful grounding techniques. Timing and bypass capacitors should be connected close to pin 5 in a single point ground. The transistor and 5K potentiometer are used to sample the oscillator wave form and apply an adjustable ramp to pin 3. Semelab plc. Telephone +44(0)1455 556565. Fax +44(0)1455 552612. E-mail: [email protected] Website: http://www.semelab.co.uk Prelim.3/00 IP1842 SERIES IP1843 SERIES TYPICAL PERFORMANCE CHARACTERISTICS COMP 1 8 VREF V FB 2 7 VCC I SENSE 3 6 OUTPUT R T /C T 4 5 GROUND COMP 1 14 VREF N/C 2 13 N/C V FB 3 12 VCC N/C 4 11 VC I SENSE 5 10 OUTPUT 6 9 GROUND R T /C T 7 8 POWER GROUND N/C Semelab plc. Telephone +44(0)1455 556565. Fax +44(0)1455 552612. E-mail: [email protected] Website: http://www.semelab.co.uk Prelim.3/00