EUP6514 EUTECH | Alldatasheet
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Technical content
DS6514 Ver 1.1 Aug. 2008 5V/12V Synchronous Buck PWM Controller
DESCRIPTION
The EUP6514 is a high efficiency, fixed 300kHz frequency, voltage mode, synchronous PWM controller. The device drives two low cost N-channel MOSFETs and is designed to work with 5V to 12V supply voltage, providing excellent regulation for load transients. The EUP6514 includes soft-start, frequency compensation networks nd integrates all of the controls, output adjustments, monitoring and protection functions into a single package. A power-on-reset (POR) circ uit monitors the power supply to prevent wrong logic controls. The built-in soft-start with fi xed soft-start internal prevents the output voltage from overshoot as well as limiting the input current. Adjustable over-current protection monitors the voltage drop across the RDS(ON) of the lower MOSFET, with no current sense resistor required. The EUP6514 is available in 8-pins SOP package. Pulling and holding the voltage on OPS pin below 0.1V with an open drain device shuts down the controller.
FEATURES
z Operating with 5~12V Supply Voltage z 300 kHz Fixed Frequency Oscillator z Built-In Feedback Compensation -Voltage-mode PWM Control with 0 to 100% Duty Ratio z Fast Transient Response -High-Speed GM Amplifier z Drives All Low Cost N-Channel MOSFETs -Adaptive Shoot-Through Protection z Adjustable Over-Current Protection -Using RDS(ON) of the Low-side MOSFET z Built-In Soft-Start z Shutdown Control using an External z Available in SOP-8 z RoHS Compliant and 100% Lead (Pb)-Free
APPLICATIONS
z High Current, up to 20A, DC-DC Converter z Telecomm Equipments z IA Equipments Typical Application Circuit Figure 1.
DS6514 Ver 1.1 Aug. 2008 Pin Configurations Package Type Pin Configurations SOP-8 Pin Description PIN PIN DESCRIPTION
1 BOOT
Bootstrap supply pin for the upper gate driver. Connect the bootstrap capacitor between BOOT pin and the PHASE pin. The bootstrap capacitor provides the charge to turn on the upper MOSFET.
2 UGATE
Upper gate driver output. Connect to the gate of high-side power N-Channel MOSEFT. This pin is monitored by the adaptive shoot-through protection circuitry to determine when the upper MOSFET has turned off.
3 GND
Both signal and power ground for the IC. All voltage levels are measured with respect to this pin. Ties the pin directly to the low-side MOSFET source and ground plane with the lowest impedance.
4 LGATE
Lower gate drive output. Connect to the gate of low-side power N-Channel MOSFET. This pin is monitored by the adaptive shoot-through protection circuitry to determine when the lower MOSFET has turned off. 5 VCC Connect this pin to a well-decoupled 5V or 12V bias supply. It is also the positive supply for the lower gate driver, LGATE. 6 FB Switcher feedback voltage. This pin is the inverting input of the error amplifier. FB senses the switcher output through an external resistor divider network.
7 OPS
This pin provides multi-function of the over-current setting, UGATE turn-on POR sensing, and shut-down features. Connecting a resistor (ROCSET) between OPS and PHASE pins sets the over-current trip point. Pulling the pin to ground resets the device and all external MOSFETs are turned off allowing the output voltage power rails to float. This pin is also used to detect V IN in power on stage and issues an internal POR signal.
8 PHASE Connect this pin to the source of the upper MOSEFT and the drain of the lower
MOSFET.
DS6514 Ver 1.1 Aug. 2008 Block Diagram Figure 2.
DS6514 Ver 1.1 Aug. 2008
Ordering Information
Order Number Package Type Marking Operating Temperature Range EUP6514DIR1 SOP-8 xxxxx P6514 -40 °C to 85°C EUP6514 □ □ □ □ Lead Free Code 1 : L e a d F r e e 0 : L e a d P a c k i n g R : T a p e & R e e l Operating temperature range I: Industry Standard Package Type D : S O P
DS6514 Ver 1.1 Aug. 2008 Absolute Maximum Ratings PHASE to GND BOOT to GND Package Thermal Resistance ESD Susceptibility Recommended Operating Conditions
Electrical Characteristics
EUP6514 Symbol Parameter Conditions Min. Typ. Max. Unit VCC Supply Current ICC Norminal Supply Current UGATE and LGATE open 2 5 mA ICCS Shutdown Supply Current 1.2 2.5 mA Power-on Reset VCCRTH POR Threshold V CC Rising 4.2 4.5 V VCCHYS Hysteresis 200 400 mV Switcher Reference VREF Reference V oltage V CC=12V 0.784 0.8 0.816 V Oscillator fOSC Free Running Trequency V CC=12V 250 300 360 kHz Ramp Amplitude ∆VOSC V CC=12V 1.5 V P-P Error Amplifier DC Gain 80 dB FP1 First Pole Frequency 1 Hz FZ Zero Frequency 1 kHz FP2 Second Pole Frequency 400 kHz FB Input Current 0.1 µA PWM Controller Gate Drivers RUGATE_H UGATE source Rdson V CC=12V , IUGATE=10mA 5 8 Ω RUGATE_L UGATE sink Rdson V UGATE=1V , IUGATE=10mA 3 6 Ω RLGATE_H LGATE source Rdson V CC=12V , ILGATE=10mA 5 8 Ω RLGATE_L LGATE sink Rdson V LGATE=1V , IUGA TE=10mA 3 6 Ω TDT Dead Time 50 ns Protection UVP Under V oltage Level FB Falling 68 73 78 % IOC OC Current Source V PHASE=0 35 40 45 µA Over-current Reference V oltage 0.4 V TSS Soft-Start Interval 4 mS VOPS_SHUT OPS Shutdown Threshold Falling V OPS 0.08 0.1 0.13 V
DS6514 Ver 1.1 Aug. 2008 Typical Operating Characteristics
DS6514 Ver 1.1 Aug. 2008 Typical Operating Characteristics (continued)
DS6514 Ver 1.1 Aug. 2008 Typical Operating Characteristics (continued)
DS6514 Ver 1.1 Aug. 2008 Under Voltage Protection The voltage at FB pin is monitored and protected against UV (under voltage). The UV threshold is the FB or FBL under 80%. UV detection has 15 µs triggered delay. A hiccup restart sequence will be operating until UV state is exited. Figure 6. PWM Layout Considerations MOSFETs switch very fast and efficiently. The speed with which the current transitions form one device to another causes voltage spikes across the interconnecting impedances and parasitic circuit elements. The voltage spikes can degrade efficiency and radiate noise, that results in over-voltage stress on devices. Careful component placement layout and printed circuit design can minimize the voltage spikes induced in the converter. Consider, as an example, the turn-off, the upper MOSFE T was carryin g the full load current. During turn-off, current stops flowing in the upper MOSFET and is picked up by the low side MOSFET or schottky diode. Any inductance in the switched current path generates a large voltage spike during the switching interval. Careful component selections, layout of the critical components, and use shorter and wider PCB traces help in minimizing the magnitude of voltage spikes. There are two sets of critical components in a DC-DC converter using the EUP6514. The switching power components are most critical because they switch large amounts of energy, and as such, they tend to generate equally large amounts of noise. The critical small signal components are those connected to sensitive nodes or those supplying critical bypass current. The power components and the PWM controller should be placed firstly. Place the input capacitors, especially the high-freque ncy ceramic decoupling capacitors, close to the power switches. Place the output inductor and output capacitors between the MOSEFTs and the load. Also locate the PWM controller near by MOSFETs. A multi-layer printed circuit board is recommended.
DS6514 Ver 1.1 Aug. 2008 Packaging Information SOP-8 MILLIMETERS INCHES SYMBOL S MIN. MAX. MIN. MAX. A 1.35 1.75 0.053 0.069 A1 0.10 0.25 0.004 0.010 D 4.90 0.193 E 5.80 6.20 0.228 0.244 E1 3.90 0.153 L 0.40 1.27 0.016 0.050 b 0.31 0.51 0.012 0.020 e 1.27 0.050