NIKO-SEM 5 Bit Programmable Synchronous Buck Converter with Dual LDOs N3004 GENERAL DESCRIPTION FEATURES The N3004 is a 5 bit TTL-compatible input, digital-to-analog (DAC) programmable, synchronous buck converter with dual LDOs controller designed specifically to power the Pentium ® II as well as the next generation of P6 family or other high performance core logic in desktop personal computer and file servers CPU applications. The N3004 switching section provides programmability of output voltage from 1.3V to 2.05V in 50mV steps and 2.0V to 3.5V in 100 mV increments and the linear sections use external N-Channel power MOSFETs to provide fixed output voltages of 1.5V for GTL bus and 2.5V for clock. The N3004 monitors all the output voltages. A signal Power-Good signal is issued when the core is within ±15% of the DAC setting. Additional features are built-in over-voltage, over-current protections for the core output and logic compatible shutdown. z Synchronous operation with high efficiency z TTL-compatible 5 bit DAC, output voltage selection from 1.3V to 3.5V programmable z Fast transient response z Provides 2 regulated voltages, 1.5V and 2.5V for linear section z Power-Good output voltage monitor z Over-Voltage and Over-Current protection z Logic level enable input z High performance and low cost solution APPLICATIONS z Powering Pentium, ® II, III or Deschutes, K6 and other advanced processor z High power DC to DC controller with triple output supplies TYPICAL APPLICATION 12V 5V + + ENABLE VID 0~4 LINEAR SECTION VCORE SWITCHING SECTION + POWER-GOOD 3.3V + 1.5V GTC BUS + 2.5V CLOCK + N3004, Motherboard Power Regulation for Computers 1 JAN-10-Y02 NIKO-SEM 5 Bit Programmable Synchronous Buck Converter with Dual LDOs N3004 ABSOLUTE MAXIMUM RATINGS PARAMETER VALUE Supply Voltage (V5 to GND) Supply Voltage (V12 to GND) Thermal Resistance Junction to Case, θJC Thermal Resistance Junction to Ambient, θJA Operating Temperature Range Storage Temperature Range Junction Operating Temperature Lead Temperature (Soldering, 10 Seconds) 10V 20V 25°C/W 85°C/W 0 to 70°C -65 to +150°C 0 to +125°C 300°C ELECTRICAL SPECIFICATIONS <Unless otherwise specified: V5 = 5V, V12 = 12V and TA = 25°C> PARAMETER CONDITIONS MIN TYP 0.99Vs Vs MAX UNITS SWITCHING SECTION DAC Output Voltage (Note 1) DAC Output Line Regulation DAC Output Temp. Variation VID Input LO VID Input HI VID Input Internal Pull-Up Resistor to V5 1.01Vs 0.1 0.5 0.4 2 27 V % % V V KΩ POWER GOOD SECTION Power Good Threshold Voltage Power Good Output LO Power Good Output HI Soft Star Current UVLO Threshold for V12 UVLO Hysterises for V12 UVLO Threshold for V5 UVLO Hysterises for V5 85 IL = 3mA RL = 5KΩ pull up to 5V SOFT START SECTION CS+ =0V, CS- =5V 9.2 0.3 Supply ramping up 4.1 0.2 ERROR COMPARATOR SECTION -2 2 0.4 V V 10 UVLO SECTION Supply ramping up VDIFF = 10mV % 4.8 Input Bias Current Input Offset Voltage Delay to Output 115 10 0.4 4.3 0.3 μA 10.8 .05 4.5 0.4 V V V V 2 μA +2 100 mV nS JAN-10-Y02 NIKO-SEM 5 Bit Programmable Synchronous Buck Converter with Dual LDOs PARAMETER CONDITIONS N3004 MIN TYP MAX UNITS 160 200 240 μA +5 2 mV % CURRENT LIMIT SECTION C.S Threshold Set Current C.S Comparator Offset Voltage Hiccup Duty Cycle Operating Supply Current Rise Time Fall Time Dead Band Time Oscillator Frequency Oscillator Valley Oscillator Peak -5 Css = 0.1μF SUPPLY CURRENT CL=3000 pF V5 V12 OUTPUT DRIVERS SECTION CL = 3,000pF CL = 3,000pF CL = 3,000pF 100 OSCILLATOR SECTION CL = 150pF 20 14 60 60 200 mA 100 130 300 nS nS nS 0.2 KHz V V 1.60 2 V μA 220 V5 LINEAR SECTIONS VFB1 & VFB2 Input Bias Current 1.40 IDRIVER1 or IDRIVER2 1.50 50 mA Note 1: Vs refers to the set point voltage given in Table 1. PIN CONFIGURATIONS 3 JAN-10-Y02 NIKO-SEM 5 Bit Programmable Synchronous Buck Converter with Dual LDOs N3004 PIN DEFINITIONS Pin # Pin Name Pin Function Description The oscillator frequency is programmed by connecting an external capacitor from this pin to GND. Operation in range of 50 KHz to 500 KHz. 2 LIN1 Gate drive output regulator, Linear 1 for GTL+ or Clock supply. 3 VFB1 Feedback input for LIN1. 4 VFB2 Feedback input for LIN2. 5 V5 5V supply voltage. 6 PGD* Open collector logic output, high if VO within 10% of set point. Current sense input (Negative), connected to the Source of the power 7 CSMOSFET for the core supply. Current sense input (Positive), connected to the Drain of the power MOSFET for the core supply. An external resistor programs the C.S threshold 8 CS+ depending on the RDS(ON) of the power MOSFET. An external capacitor is placed in parallel with the programming resistor to provide high frequency noise filtering. 9 HDRV High side driver output. This pin serves as the ground pin and must be connected directly to the 10 GND ground plane. A high frequency capacitor (0.1 to 1μF) must be connected directly from V5 and V12 pins to this pin for noise free operation. 11 LDRV Low side driver output. 12V supply voltage for LINEAR section. A high frequency capacitor (0.1 to 12 V12 1μF) must be connected directly from this pin to GND pin in order to supply the peak current to the power MOSFET during the transients. This pin provides the soft start for the switching regulator. An internal current source charges an external capacitor that is connected from this 13 SS pin to the GND which ramps up the outputs of the switching regulator, preventing the outputs from overshooting as well as limiting the input current. The second function of the soft start cap is to provide long off time (HICCUP) for the synchronous MOSFET during current limiting. 14 VFB3 Feedback input for VCORE. 15 VID4* Programming input (MSB). 16 VID3* Programming input. 17 VID2* Programming input. 18 VID1* Programming input. 19 VID0* Programming input (LSB). 20 LIN2 Gate drive output regulator, Linear 2 for GTL+ or Clock supply. * : All logic level inputs and outputs are open collector TTL compatible. 1 CT 4 JAN-10-Y02 NIKO-SEM 5 Bit Programmable Synchronous Buck Converter with Dual LDOs N3004 OUTPUT SET POINT VOLTAGE vs VID CODES − Table 1 − Vs VID4 VID3 VID2 VID1 VID0 1.30 1.35 1.40 1.45 1.50 1.55 1.60 1.65 1.70 1.75 1.80 1.85 1.90 1.95 2.00 2.05 2.00 2.10 2.20 2.30 2.40 2.50 2.60 2.70 2.80 2.90 3.00 3.10 3.20 3.30 3.40 3.50 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 5 JAN-10-Y02 NIKO-SEM 5 Bit Programmable Synchronous Buck Converter with Dual LDOs N3004 APPLICATION CIRCUIT + VID 0 HDRV VID 1 CS- VID 2 VID 2 LDRV VID 3 VID 3 VFB3 VID 4 VID 4 LIN1 V12 LIN2 + 1uF 150pF + + + 100 10K 3.3V SS VFB2 CT VFB1 PGD GND + 100 100 1K 680uF 0.01uF MOSFET P3055LD x 2 0.01uF 1.5V GTC BUS + 100 680uF 1K 2.5V CLOCK 100 150 10K 3.3V + CS+ VID 1 + 1uF + SBD 1A/30V Short or 5 OHM VID 0 12V 0.1uF 470pF N3004 VCC 1500uF x 5 VCORE + 2.21K 1uF 2.5uH 10 + 0.1uF 220pF + 1000uF MOSFET P50N02L x 2 1000uF x 2 10 2 uH 5V + 220uF 10K P.G 0.1uF 6 JAN-10-Y02 NIKO-SEM 5 Bit Programmable Synchronous Buck Converter with Dual LDOs N3004 SOIC-20 (DW) MECHANICAL DATA Dimension mm Min. Typ. Dimension Max. mm Min. Typ. Max. A 12.6 13.0 H 0.4 1.27 B 7.3 7.7 I 0.23 0.32 C 10 10.65 J 0.25 0.74 D 0.33 0.51 K 0° 8° E 1.27 F 2.1 G 0.1 2.3 L 2.5 M 0.3 N 7 JAN-10-Y02