UCC1800/1/2/3/4/5 UCC2800/1/2/3/4/5 UCC3800/1/2/3/4/5 Low-Power BiCMOS Current-Mode PWM FEATURES DESCRIPTION • 100µA Typical Starting Supply Current The UCC1800/1/2/3/4/5 family of high-speed, low-power integrated circuits contain all of the control and drive components required for off-line and DC-to-DC fixed frequency current-mode switching power supplies with minimal parts count. • 500µA Typical Operating Supply Current • Operation to 1MHz • Internal Soft Start • Internal Fault Soft Start • Internal Leading-Edge Blanking of the Current Sense Signal • 1 Amp Totem-Pole Output • 70ns Typical Response from Current-Sense to Gate Drive Output • 1.5% Tolerance Voltage Reference • Same Pinout as UC3842 and UC3842A Part Number UCCx800 UCCx801 UCCx802 UCCx803 UCCx804 UCCx805 These devices have the same pin configuration as the UC1842/3/4/5 family, and also offer the added features of internal full-cycle soft start and internal leading-edge blanking of the current-sense input. The UCC1800/1/2/3/4/5 family offers a variety of package options, temperature range options, choice of maximum duty cycle, and choice of critical voltage levels. Lower reference parts such as the UCC1803 and UCC1805 fit best into battery operated systems, while the higher reference and the higher UVLO hysteresis of the UCC1802 and UCC1804 make these ideal choices for use in off-line power supplies. The UCC180x series is specified for operation from –55oC to +125oC, the UCC280x series is specified for operation from –40oC to +85oC, and the UCC380x series is specified for operation from 0oC to +70oC. Maximum Duty Cycle 100% 50% 100% 100% 50% 50% Reference Voltage 5V 5V 5V 4V 5V 4V Turn-On Threshold 7.2V 9.4V 12.5V 4.1V 12.5V 4.1V Turn-Off Threshold 6.9V 7.4V 8.3V 3.6V 8.3V 3.6V BLOCK DIAGRAM UDG92009-3 03/99 Powered by ICminer.com Electronic-Library Service CopyRight 2003 UCC1800/1/2/3/4/5 UCC2800/1/2/3/4/5 UCC3800/1/2/3/4/5 CONNECTION DIAGRAMS ABSOLUTE MAXIMUM RATINGS (Note 1) VCC Voltage (Note 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.0V VCC Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30.0mA OUT Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±1.0A OUT Energy (Capacitive Load) . . . . . . . . . . . . . . . . . . . 20.0µJ Analog Inputs (FB, CS) . . . . . . . . . . . . . . . . . . . . –0.3V to 6.3V Power Dissipation at TA < +25°C (N or J Package) . . . . . 1.0W Power Dissipation at TA < +25°C (D Package). . . . . . . . 0.65W Storage Temperature Range. . . . . . . . . . . . . –65°C to +150°C Lead Temperature (Soldering, 10 Seconds) . . . . . . . . +300°C Note 1: All voltages are with respect to GND. All currents are positive into the specified terminal. Consult Unitrode databook for information regarding thermal specifications and limitations of packages. Note 2: In normal operation VCC is powered through a current limiting resistor. Absolute maximum of 12V applies when VCC is driven from a low impedance source such that ICC does not exceed 30mA. TSSOP-8 (Top View) PW Package Temperature Range –55°C to +125°C –40°C to +85°C 0°C to +70°C COMP REF 8 2 FB VCC 7 3 CS OUT 6 4 RC GND 5 DIL-8, SOIC-8 (Top View) J or N, D Package TEMPERATURE AND PACKAGE SELECTION UCC1800 UCC2800 UCC3800 1 Available Packages J N, D, PW N, D, PW COMP 1 8 REF FB 2 7 VCC CS 3 6 OUT RC 4 5 GND ORDERING INFORMATION UCC 80 PACKAGE PRODUCT OPTION TEMPERATURE RANGE ELECTRICAL CHARACTERISTICS Unless otherwise stated, these specifications apply for –55°C ≤ TA ≤ +125°C for UCC180x; –40°C ≤ TA ≤ +85°C for UCC280x; 0°C ≤ TA ≤ +70°C for UCC380x; VCC=10V (Note 3); RT=100k from REF to RC; CT=330pF from RC to GND; 0.1µF capacitor from VCC to GND; 0.1µF capacitor from VREF to GND. TA=TJ. PARAMETER TEST CONDITIONS UCC180X UCC280X MIN TYP UCC380X MAX MIN UNITS TYP MAX TJ=+25°C, I=0.2mA, UCCx800/1/2/4 4.925 5.00 5.075 4.925 5.00 5.075 TJ=+25°C, I=0.2mA, UCCx803/5 3.94 4.00 4.06 Reference Section Output Voltage 4.06 3.94 4.00 V Load Regulation 0.2mA<I<5mA 10 30 10 25 mV Total Variation UCCx800/1/2/4 (Note 7) 4.88 5.00 5.10 4.88 5.00 5.10 V UCCx803/5 (Note 7) 3.90 4.00 4.08 3.90 4.00 4.08 Output Noise Voltage 10Hz ≤ f ≤ 10kHz, TJ=+25°C (Note 9) Long Term Stability TA=+125°C, 1000 Hours (Note 9) Output Short Circuit V 130 130 µV 5 5 mV –5 –35 –5 –35 mA Oscillator Section Oscillator Frequency Temperature Stability UCCx800/1/2/4 (Note 4) 40 46 52 40 46 52 kHz UCCx803/5 (Note 4) 26 31 36 26 31 36 kHz 2.25 2.40 2.55 2.25 2.40 (Note 9) 2.5 Amplitude peak-to-peak Oscillator Peak Voltage Powered by ICminer.com Electronic-Library Service CopyRight 2003 2.45 2 2.5 2.45 % 2.55 V V UCC1800/1/2/3/4/5 UCC2800/1/2/3/4/5 UCC3800/1/2/3/4/5 ELECTRICAL CHARACTERISTICS Unless otherwise stated, these specifications apply for –55°C ≤ TA ≤ +125°C for UCC180x; –40°C ≤ TA ≤ +85°C for UCC280x; 0°C ≤ TA ≤ +70°C for UCC380x; VCC=10V (Note 3); RT=100k from REF to RC; CT=330pF from RC to GND; 0.1µF capacitor from VCC to GND; 0.1µF capacitor from VREF to GND. TA=TJ. PARAMETER TEST CONDITIONS UCC180X UCC280X UCC380X UNITS Error Amplifier Section Input Voltage COMP=2.5V; UCCx800/1/2/4 2.44 2.50 2.56 2.44 2.50 2.56 COMP=2.0V; UCCx803/5 1.95 2.0 2.05 1.95 2.0 2.05 1 –1 3.5 0.4 –0.8 –0.2 –1 Input Bias Current Open Loop Voltage Gain 60 COMP Sink Current FB=2.7V, COMP=1.1V 0.3 COMP Source Current FB=1.8V, COMP=REF–1.2V –0.2 Gain Bandwidth Product (Note 9) 80 –0.5 60 2 1 µA 2.5 mA 80 –0.5 V dB –0.8 2 mA MHz PWM Section Maximum Duty Cycle Minimum Duty Cycle UCCx800/2/3 97 99 100 97 99 100 UCCx801/4/5 48 49 50 48 49 50 COMP=0V 0 % 0 % 1.80 V/V Current Sense Section Gain (Note 5) Maximum Input Signal COMP=5V (Note 6) 1.65 0.9 1.0 –200 Input Bias Current CS Blank Time 50 Over-Current Threshold COMP to CS Offset 1.10 CS=0V 100 1.80 1.10 1.65 1.0 1.1 0.9 200 –200 150 50 100 1.1 V 200 nA 150 ns 1.42 1.55 1.68 1.42 1.55 1.68 V 0.45 0.90 1.35 0.45 0.90 1.35 V 0.1 0.4 0.1 0.4 V Output Section OUT Low Level OUT High VSAT (VCC-OUT) I=20mA, all parts I=200mA, all parts 0.35 0.90 0.35 0.90 V I=50mA, VCC=5V, UCCx803/5 0.15 0.40 0.15 0.40 V I=20mA, VCC=0V, all parts 0.7 1.2 0.7 1.2 V I=–20mA, all parts 0.15 0.40 0.15 0.40 V I=–200mA, all parts 1.0 1.9 1.0 1.9 V I=–50mA,VCC=5V, UCCx803/5 0.4 0.9 0.4 0.9 V Rise Time CL=1nF 41 70 41 70 ns Fall Time CL=1nF 44 75 44 75 ns 7.2 7.8 7.2 7.8 V Undervoltage Lockout Section Start Threshold (Note 8) Stop Threshold (Note 8) Start to Stop Hysteresis UCCx800 6.6 6.6 UCCx801 8.6 9.4 10.2 8.6 9.4 10.2 V UCCx802/4 11.5 12.5 13.5 11.5 12.5 13.5 V UCCx803/5 3.7 4.1 4.5 3.7 4.1 4.5 V UCCx1800 6.3 6.9 7.5 6.3 6.9 7.5 V UCCx1801 6.8 7.4 8.0 6.8 7.4 8.0 V UCCx802/4 7.6 8.3 9.0 7.6 8.3 9.0 V UCCx803/5 3.2 3.6 4.0 3.2 3.6 4.0 V UCCx800 0.12 0.3 0.48 0.12 0.3 0.48 V UCCx801 1.6 2 2.4 1.6 2 2.4 V UCCx802/4 3.5 4.2 5.1 3.5 4.2 5.1 V UCCx803/5 0.2 0.5 0.8 0.2 0.5 0.8 V Powered by ICminer.com Electronic-Library Service CopyRight 2003 3 UCC1800/1/2/3/4/5 UCC2800/1/2/3/4/5 UCC3800/1/2/3/4/5 ELECTRICAL CHARACTERISTICS Unless otherwise stated, these specifications apply for –55°C ≤ TA ≤ +125°C for UCC180x; –40°C ≤ TA ≤ +85°C for UCC280x; 0°C ≤ TA ≤ +70°C for UCC380x; VCC=10V (Note 3); RT=100k from REF to RC; CT=330pF from RC to GND; 0.1µF capacitor from VCC to GND; 0.1µF capacitor from VREF to GND. TA=TJ. PARAMETER TEST CONDITIONS UCC180X UCC280X UCC380X UNITS Soft Start Section COMP Rise Time FB=1.8V, Rise from 0.5V to REF–1V 4 10 4 10 ms 0.1 0.2 0.1 0.2 mA Overall Section Start-up Current VCC < Start Threshold Operating Supply Current FB=0V, CS=0V VCC Internal Zener Voltage ICC=10mA (Note 8) VCC Internal Zener Voltage Minus UCCx802/4 Start Threshold Voltage 0.5 1.0 12 13.5 15 0.5 1.0 0.5 1.0 mA 12 13.5 15 V 0.5 1.0 V Note 3: Adjust VCC above the start threshold before setting at 10V. Note 4: Oscillator frequency for the UCCx800, UCCx802 and UCCx803 is the output frequency. Oscillator frequency for the UCCx801, UCCx804 and UCCx805 is twice the output frequency. ∆ VCOMP Note 5: Gain is defined by: A = 0 ≤ VCS ≤ 0.8V . ∆ VCS Note 6: Parameter measured at trip point of latch with Pin 2 at 0V. Note 7: Total Variation includes temperature stability and load regulation. Note 8: Start Threshold, Stop Threshold and Zener Shunt Thresholds track one another. Note 9: Guaranteed by design. Not 100% tested in production. PIN DESCRIPTIONS effective CS to OUT propagation delay. Note, however, that the minimum non-zero On-Time of the OUT signal is directly affected by the leading-edge-blanking and the CS to OUT propagation delay. COMP: COMP is the output of the error amplifier and the input of the PWM comparator. Unlike other devices, the error amplifier in the UCC3800 family is a true, low output-impedance, 2MHz operational amplifier. As such, the COMP terminal can both source and sink current. However, the error amplifier is internally current limited, so that you can command zero duty cycle by externally forcing COMP to GND. The over-current comparator is only intended for fault sensing, and exceeding the over-current threshold will cause a soft start cycle. FB: FB is the inverting input of the error amplifier. For best stability, keep FB lead length as short as possible and FB stray capacitance as small as possible. The UCC3800 family features built-in full cycle Soft Start. Soft Start is implemented as a clamp on the maximum COMP voltage. GND: GND is reference ground and power ground for all functions on this part. CS: CS is the input to the current sense comparators. The UCC3800 family has two different current sense comparators: the PWM comparator and an over-current comparator. OUT: OUT is the output of a high-current power driver capable of driving the gate of a power MOSFET with peak currents exceeding ± 750mA. OUT is actively held low when VCC is below the UVLO threshold. The UCC3800 family contains digital current sense filtering, which disconnects the CS terminal from the current sense comparator during the 100ns interval immediately following the rising edge of the OUT pin. This digital filtering, also called leading-edge blanking, means that in most applications, no analog filtering (RC filter) is required on CS. Compared to an external RC filter technique, the leading-edge blanking provides a smaller Powered by ICminer.com Electronic-Library Service CopyRight 2003 The high-current power driver consists of FET output devices, which can switch all of the way to GND and all of the way to VCC. The output stage also provides a very low impedance to overshoot and undershoot. This means that in many cases, external schottky clamp diodes are not required. 4 UCC1800/1/2/3/4/5 UCC2800/1/2/3/4/5 UCC3800/1/2/3/4/5 PIN DESCRIPTIONS (cont.) used as the logic power supply for high speed switching logic on the IC. RC: RC is the oscillator timing pin. For fixed frequency operation, set timing capacitor charging current by connecting a resistor from REF to RC. Set frequency by connecting a timing capacitor from RC to GND. For best performance, keep the timing capacitor lead to GND as short and direct as possible. If possible, use separate ground traces for the timing capacitor and all other functions. When VCC is greater than 1V and less than the UVLO threshold, REF is pulled to ground through a 5k ohm resistor. This means that REF can be used as a logic output indicating power system status. It is important for reference stability that REF is bypassed to GND with a ceramic capacitor as close to the pin as possible. An electrolytic capacitor may also be used in addition to the ceramic capacitor. A minimum of 0.1µF ceramic is required. Additional REF bypassing is required for external loads greater than 2.5mA on the reference. The frequency of oscillation can be estimated with the following equations: UCCx800/1/2/4: F = 1.5 R •C UCCx803, UCCx805: F = To prevent noise problems with high speed switching transients, bypass REF to ground with a ceramic capacitor very close to the IC package. 10 . R •C where frequency is in Hz, resistance is in ohms, and capacitance is in farads. The recommended range of timing resistors is between 10k and 200k and timing capacitor is 100pF to 1000pF. Never use a timing resistor less than 10k. VCC: VCC is the power input connection for this device. In normal operation VCC is powered through a current limiting resistor. Although quiescent VCC current is very low, total supply current will be higher, depending on OUT current. Total VCC current is the sum of quiescent VCC current and the average OUT current. Knowing the operating frequency and the MOSFET gate charge (Qg), average OUT current can be calculated from: To prevent noise problems, bypass VCC to GND with a ceramic capacitor as close to the VCC pin as possible. An electrolytic capacitor may also be used in addition to the ceramic capacitor. IOUT = Q g × F . REF: REF is the voltage reference for the error amplifier and also for many other functions on the IC. REF is also The UCC3800/1/2/3/4/5 oscillator generates a sawtooth waveform on RC. The rise time is set by the time constant of RT and CT. The fall time is set by CT and an internal transistor on-resistance of approximately 125Ω. During the fall time, the output is off and the maximum duty cycle is reduced below 50% or 100% depending on the part number. Larger timing capacitors increase the discharge time and reduce the maximum duty cycle and frequency. Figure 2. Error amplifier gain/phase response. Figure 1. Oscillator. Powered by ICminer.com Electronic-Library Service CopyRight 2003 5 UCC1800/1/2/3/4/5 UCC2800/1/2/3/4/5 UCC3800/1/2/3/4/5 4.00 1000 Oscillator Freq. (kHz) 3.98 3.96 VREF (V) 3.94 3.92 3.90 3.88 10 0p F 100 20 0p 33 F 0p F 3.86 3.84 1n F 10 3.82 4 4.2 4.4 4.6 4.8 5 5.2 VCC (V) 5.4 5.6 5.8 10 6 100 1000 RT (k ) Figure 3. UCC1803/5 VREF vs. VCC; ILOAD = 0.5mA. Figure 4. UCC1800/1/2/4 oscillator frequency vs. RT and CT. 1000 100 Maximum Duty Cycle (%) 95.5 F 95 100 1000 10 100 RT (k ) 1000 Oscillator Frequency (kHz) Figure 5. UCC1803/5 oscillator frequency vs. RT and CT. Figure 6. UCC1800/2/3 maximum duty cycle vs. oscillator frequency. 50 16 49.5 14 12 49 CT ICC (mA) pF 00 pF 30 =3 00 =2 pF 48 nF ,1 0V =1 C 10 =1 CT 48.5 CT Maximum Duty Cycle (%) pF 96 1n 10 00 96.5 F 10 =1 97 pF 0p pF F 33 CT 0p 30 20 97.5 00 F =3 0p 98 =2 10 98.5 CT 100 99 CT Oscillator Freq. (kHz) 99.5 VC 8 F n V, 1 =8 C VC 6 ad 47.5 4 47 VCC = VCC = 8V, 2 0 0 46.5 10 100 1000 100 200 300 400 500 600 700 No Load 800 900 1000 Oscillator Frequency (kHz) Oscillator Frequency (kHz) Figure 7. UCC1801/4/5 maximum duty cycle vs. oscillator frequency. Powered by ICminer.com Electronic-Library Service CopyRight 2003 o Lo 10V, N Figure 8. UCC1800 ICC vs. oscillator frequency. 6 UCC1800/1/2/3/4/5 UCC2800/1/2/3/4/5 UCC3800/1/2/3/4/5 8 500 450 7 UCC1803/5 , 0V C VC ICC (mA) 5 400 =1 Dead Time (ns) 6 F 1n nF 1 V, 8 C= 4 VC 3 VCC = 2 d o Loa 10V, N 250 UCC1800/1/2/4 200 100 50 0 100 200 300 400 500 600 700 800 100 900 1000 Figure 8. UCC1805 ICC vs. oscillator frequency. 1.0 0.9 Slope = 1.8mV/°C 0.7 0.6 0 -55-50 -25 0 25 50 75 100 125 Temperature (°C) Figure 10. COMP to CS offset vs. temperature, CS = 0V. Powered by ICminer.com Electronic-Library Service CopyRight 2003 300 400 500 600 700 Figure 9. Dead time vs. CT, RT = 100k. 1.1 0.8 200 CT (pF) Oscillator Frequency (kHz) COMP to CS Offset (Volts) 300 150 d , No Loa VCC = 8V 1 0 0 350 7 800 900 1000 IMPORTANT NOTICE Texas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinue any product or service without notice, and advise customers to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. All products are sold subject to the terms and conditions of sale supplied at the time of order acknowledgement, including those pertaining to warranty, patent infringement, and limitation of liability. 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