SC198A Semtech, SC198A Datasheet
SC198A
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SC198A Summary of contents
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... Each converter is capable of supplying up to 800mA of average current at one of eight programmable output voltages used as microprocessor supply voltages. The SC198A uses a single control logic block for the two converters, but their controls can be set independently. The device uses a fl exible clocking method allowing the user to set the fi xed internal 1MHz oscillator or synchro- nize the clock to an external source ...
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... Semtech Lot No. xxxx = Semtech Lot No. Ordering Information SC198AMLTRT SC198AEVB 16 Notes: (1) Available in tape and reel only. A reel contains 3,000 devices. VINB 15 (2) Lead-free package only. Device is WEEE and RoHS compliant. LXB 14 GNDB 13 VOUTB 12 CTLB0 11 10 www.DataSheet4U.com Device Package (1) (2) MLPQ-20 Evaluation Board SC198A 2 ...
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... LXA, LXB = Open ENA ENB V = 5.5V 0V, PMOS IN LX LXB V = 5.5V NMOS 100mA LXA LXB www.DataSheet4U.com = 25°C for both outputs. A Min Typ 2.7 4.0 -3 OUT = 300mA OUT = 300mA OUT = 1.8V OUT = 5.0V IN 1.2 IN 0.1 0.1 -2 0.1 0.35 SC198A (2) (°C/ Max Units 5 0.2 %/V 0.0008 %/ μA 1 μA 1 μA μA Ω 3 ...
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... See Output Voltage Options table in the Application Information section. (2) For ENA, ENB, SYNC, CTLA0, CTLA1, CTLA2, CTLB0, CTLB1, CTLB2. Conditions 100mA DSN LXA LXB OSC HI HYSR Decreasing V UVL IH IL www.DataSheet4U.com Min Typ 0.25 0.95 1.1 1.25 145 10 2.4 2 1.6 SC198A Max Units Ω 1.25 MHz MHz 0.75 MHz °C ° ...
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... Oscillator synchronization input — connect to VIN for forced PWM mode, ground for power-save mode or connect to an external clock for frequency synchronization. Reference supply input Not connected — Leave open Enable pin for output A Thermal pad for heatsinking purposes — connect to ground plane using multiple vias — not con- nected internally SC198A www.DataSheet4U.com 5 ...
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... P Limit A B Amp PWM PWM Comp Comp Switching Control Logic Error Amp A VREF1 Voltage VREF2 References VREF3 www.DataSheet4U.com VREF1 Current P Limit Amp Amp N Limit Amp VREF2 Error Voltage Amp VREF3 Select B SC198A 15 VINB 14 LXB 13 GNDB 16 ENB 12 VOUTB 11 CTLB0 10 CTLB1 9 CTLB2 8 GNDR 6 ...
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... Side 1.8V PSAVE OUT V = 1.0V PSAVE OUT V = 1.8V PWM OUT V = 1.0 PWM OUT 0.001 0.01 0.1 Load (A) Effi ciency vs. Load 5.5V, Side 1.8V PSAVE OUT V = 1.0V PSAVE OUT V = 1.8V PWM OUT V = 1.0 PWM OUT 0.001 0.01 0.1 Load (A) Load Regulation — V =1.8V, V OUT V OUT 0.001 0.01 0.1 Load (A) SC198A 1 1 =3. 1.8V PWM V = 1.0 PWM OUT 1 7 ...
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... Time (200μs/div) 1.854 1.836 1.818 1.8 1.782 1.764 1.746 2.7 4.38 4.94 5.5 = 3.3V 0mA OUTB OUTB (100mV/div) (100mV/div) (5.0mV/div) (200mV/div) (200mV/div) (1.0A/div) SC198A www.DataSheet4U.com V vs. V — 1.8V Programmed Output OUT 300mA OUT I = 800mA OUT 4.38 3.26 3.82 4.94 Input (V) Crosstalk — Side A (PSAVE) Side B (PWM) V =5.0V, 25° 1.0V 80mA ...
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... Time (400ns/div) Switching Waveforms in PSAVE V =1.0V, V =3.6V, 25° 0mA OUT IN OUT (2V/div) (10mV/div) Time (20ms/div) =1.0V OUT V IN (2V/div) (10mV/div) V OUT (2V/div) (50mV/div) SC198A www.DataSheet4U.com Switching Waveforms — V =1.8V OUT =3.6V, 25° 800mA OUT Time (400ns/div) Switching Waveforms in PSAVE =1.8V, V =3.6V, 25° 80mA IN OUT Time (4μs/div) 9 ...
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... L = 4.7μH and COUT = 10μF. www.DataSheet4U.com Programmable Output Voltage The SC198A has three control pins per output to allow selection of a voltage level from eight predetermined output voltage levels (see Table 1). CAUTION — All CTL pins much be pulled high or low for proper operation (they must not be allowed to fl oat) ...
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... VOUT falls due to the load increasing above the level that the peak current will support. For the SC198A to exit PSAVE mode, the load must be increased, which causes VOUT to decrease until the PSAVE exit threshold is reached. PSAVE levels are set high to minimize the undershoot when the SC198A exits PSAVE ...
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... Applications Information (continued) Inductor Selection The SC198A was designed for optimum performance when using a 4.7μH inductor. The magnitude of the inductor current ripple is dependent on the inductor value and is determined by the equation V V OUT OUT osc This equation demonstrates the relationship between input voltage, output voltage, and inductor ripple current ...
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... Route the output voltage feedback path away from inductor and LX node to minimize noise and magnetic interference. 3. Use a ground plane to further reduce noise interference on sensitive circuit nodes. VIN GND Cin A LXA VOUTA GND GND GND Cin B LXB VOUTB SC198A www.DataSheet4U.com 13 ...
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... 100 . 106 . 110 153 . 157 . 161 E1 . 100 . 106 . 110 020 BSC 0. 50 BSC 011 . 016 . 020 aaa . 004 0. 10 bbb . 004 0. 10 SC198A 14 ...
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... CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR COMPANY’S MANUFACTURING GUIDELINES ARE MET Contact Information Semtech Corporation Power Mangement Products Division 200 Flynn Road, Camarillo, CA 93012 Phone: (805) 498-2111 Fax: (805) 498-3804 www.semtech.com SC198A www.DataSheet4U.com DIMENSIONS DIM INCHES MILLIMETERS (. 155) (3.95 122 3.10 H ...