IP2842

IP1842 SEME-LAB | Alldatasheet

Document overview

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Technical content

Prelim.3/00Semelab plc. Telephone +44(0)1455 556565. Fax +44(0)1455 552612. CURRENT MODE REGULATING PULSE WIDTH MODULATORS

FEATURES

• Guaranteed ±1% reference voltage tolerance  Guaranteed ±10% frequency tolerance  Low start–up current (<500 /G6D/G6D/G6D/G6D A)  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 VCC Supply Voltage (low impedance source) (ICC < 30mA) IO Output Current Output Energy (capacitive load) Analog Inputs (pins 2 and 3) Error Amp Output Sink Current P D Power Dissipation T amb = 25°C Derate @ Tamb > 50°C PD Power Dissipation T case = 25°C Derate @ Tcase > 25°C TSTG Storage Temperature Range TL Lead Temperature (soldering, 10 seconds) +30V Self limiting ±1A 5/G6D J –0.3V to +VCC 10mA 10mW/°C 24mW/°C –65 to 150°C +300°C ABSOLUTE MAXIMUM RATINGS (Tcase = 25°C unless otherwise stated) TOP VIEW J Package – 8 Pin Ceramic DIP N Package – 8 Pin Plastic DIP COMP VREF GROUND OUTPUT R T /CT VCC ISENSE V FB TOP VIEW COMP VREF GROUND OUTPUT POWER GROUND N/C R T /CT ISENSE N/C N/C N/C VCCV FB VC Part J –Pack N –Pack D –8D –14 Temp. Number 8 Pin 8 Pin 8 Pin 14 Pin Range IP1842 ✔ -55 to +125°C IP1843 ✔ -55 to +125°C Order Information Note: To order, add the package identifier to the part number. eg. IP1842J IP3843D-14

Prelim.3/00Semelab plc. Telephone +44(0)1455 556565. Fax +44(0)1455 552612.

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 Values in brackets are for IP1843 series. 3.6V ERROR AMP OSCILLATOR R 1V R S PWM LATCH CURRENT SENSE COMPARATOR 16V (8.4V) (0.5V) 2.5V UNDER –VOLTAGE LOCKOUT ENABLE REFERENCE REGULATOR INTERNAL BIAS 34V REG R S V STATUS LATCH REF OUTPUT VREF C OMP G ND VCC ISENSE V FB /CR TT POWER GROUND VC PIN NUMBERS 1st Number 2nd Number – N, J and 8 Pin D Packages – 14 Pin D Package. 4/7 6/10 VCC Supply Voltage 1 IO Output Current Analog Inputs (pins 2 and 3) Error Amp Output Sink Current IP1842 , IP1843 Operating Ambient Temperature Range IP2842 , IP2843 IP3842 , IP3843 /GA3/G20 30V 0 to ±200mA –0.3V to 3V 0 to 2mA –55 to 125°C –25 to 85°C 0 to 70°C Notes: 1. Lower limit set by under voltage lockout specification. RECOMMENDED OPERATING CONDITIONS

1. Test Conditions unless otherwise stated: VCC = 15V* , RT = 10k/G57 , 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). IP1842 SERIES IP1843 SERIES Prelim.3/00Semelab plc. Telephone +44(0)1455 556565. Fax +44(0)1455 552612. 4.90 5.00 5.10 62 0 62 5 0.2 0.4 4.82 5.18 52 5 30 80 160 47 52 57 0.2 1 1.7 8.3 2.42 2.50 2.58 –0.3 –2 65 90 0.7 1 60 70 –0.5 –0.8 4.6 4.8 0.7 1.1 4.95 5.00 5.05 62 0 62 5 0.2 0.4 4.90 5.10 52 5 30 80 160 47 52 57 0.2 1 1.7 8.3 2.45 2.50 2.55 –0.3 –1 65 90 0.7 1 60 70 –0.5 –0.8 4.6 4.8 0.7 1.1 IP1842/IP1843 IP3842 IP2842/IP2843 IP3843 Output Voltage Input Regulation Output Regulation Temperature Stability Total Output Variation Output Noise Voltage Long Term Stability Output Short Circuit Current Frequency Voltage stability Temperature Stability Amplitude Discharge Current Input Voltage Input Bias Current Open Loop Voltage Gain Unity Gain Bandwidth Supply Voltage Rejection Output Sink Current Output Source Current V OUT High VOUT Low IO = 1mA T J = 25°C VCC = 12V to 25V IO = 1mA to 20mA Line, Load, Temp f = 10Hz to 10kHz TJ = 25°C TJ = 125°C @ 1000Hrs VREF = 0 TJ = 25°C VCC = 12V to 25V /G44 TA = Min to Max VPIN4 Peak to Peak TJ = 25°C /G44 TA = Min to Max VPIN1 = 2.5V VO = 2V to 4V VCC = 12V to 25V VPIN2 = 2.7V V PIN1 = 1.1V VPIN2 = 2.3V V PIN1 = 4.6V VPIN2 = 2.3V R L = 15k/G57 VPIN2 = 2.7V R L = 15k/G57 V mV mV V /G6D V mV mA kHz V mA V /G6D A dB MHz dB mA V ELECTRICAL CHARACTERISTICS (Over Full Operating Temperature Range unless otherwise stated) REFERENCE SECTION OSCILLATOR SECTION ERROR AMP SECTION

2.85 3 3.15 0 . 911 . 1 60 70 –2 –10 200 400 0.1 0.4 1.5 2.2 13 13.5 12 13.5 50 150 50 150 0.7 1.1 14.5 16 17.5 7.8 8.4 9 8.5 10 11.5 7 7.6 8.2 0.3 0.5 11 15 14 17 30 34 40 2.85 3 3.15 0 . 911 . 1 60 70 –2 –10 200 400 0.1 0.4 1.5 2.2 13 13.5 12 13.5 50 150 50 150 0.7 1.1 15 16 17 7.8 8.4 9 91 0 1 1 7 7.6 8.2 0.3 0.5 11 15 14 17 30 34 40 Gain Maximum Input Signal Supply Voltage Rejection Input Bias Current Delay to Output Output Low Level Output High Level Rise Time Fall Time UVLO Saturation Upper Threshold CC ) Lower Threshold CC ) Start–up Current Operating Supply Current V CC Zener Voltage See Notes 2,3 VPIN1 = 4.6V (Note 2) VC = 12V to 25V ISINK = 20mA ISINK = 200mA ISOURCE = 20mA ISOURCE = 200mA C L = 1nF T J = 25°C C L = 1nF T J = 25°C VCC = 6V I L = 1mA

1842 Series

1843 Series

V PIN2 = 0V 1842 Series VPIN3 = 0V 1843 Series ICC = 25mA V/V V dB /G6D A ns V V ns V V V mA mA V NOTES 1. Test Conditions unless otherwise stated: VCC = 15V* , RT = 10k/G57 , 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). 2. Parameter measured at trip point of latch with VPIN2 = 0V 3. Gain defined as: /G44 VPIN1A = /G44 VPIN3 0 /GA3 VPIN3 /GA3 0.8 IP1842 SERIES IP1843 SERIES Prelim.3/00Semelab plc. Telephone +44(0)1455 556565. Fax +44(0)1455 552612. ELECTRICAL CHARACTERISTICS (Over Full Operating Temperature Range unless otherwise stated) CURRENT SENSE SECTION OUTPUT SECTION UNDER–VOLTAGE LOCKOUT SECTION TOTAL STANDBY CURRENT

tc /GBB 0.55 RTC T td /GBB R TC T Rn 1Resultant frequency f =(tc + td) For RT > 5k/G57 , 1.8Resultant frequency f /GBB (RTC T) Oscillator timing capacitor CT is charged by VREF through RT and discharged by an internal current source. During the discharge time, the internal clock signal blanks the output to the low state. Selection of R T and C T therefore determines both oscillator frequency and maximum duty cycle. Charge and discharge times are determined by the formulae: .0063 RT – 2.3 .0063 – 4( ) IP1842 SERIES IP1843 SERIES Prelim.3/00Semelab plc. Telephone +44(0)1455 556565. Fax +44(0)1455 552612. Open–Loop Laboratory Test Fixture APPLICATIONS INFORMATION 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. COMP VREF GROUND OUTPUT R T /CT VCC ISENSE V FB COMP VREF GROUND OUTPUT POWER GROUND N/C R T /CT ISENSE N/C N/C N/C VCCV FB VC Oscillator Waveforms and Maximum Duty Cycle

Prelim.3/00Semelab plc. Telephone +44(0)1455 556565. Fax +44(0)1455 552612. COMP VREF GROUND OUTPUT R T /CT VCC ISENSE V FB TYPICAL PERFORMANCE CHARACTERISTICS COMP VREF GROUND OUTPUT POWER GROUND N/C R T /CT ISENSE N/C N/C N/C VCCV FB VC