N3004

NIKO-SEM 5 Bit Programmable Synchronous Buck Converter with Dual LDOs FEATURES N3004 GENERAL DESCRIPTION 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. Synchronous operation with high efficiency TTL-compatible 5 bit DAC, output voltage selection from 1.3V to 3.5V programmable Fast transient response Provides 2 regulated voltages, 1.5V and 2.5V for linear section Power-Good output voltage monitor Over-Voltage and Over-Current protection Logic level enable input High performance and low cost solution APPLICATIONS Powering Pentium, ® II, III or Deschutes, K6 and other advanced processor High power DC to DC controller with triple output supplies TYPICAL APPLICATION 12V 5V + + ENABLE VID 0~4 LINEAR SECTION SWITCHING SECTION VCORE + POWER-GOOD 1.5V GTC BUS 3.3V + + 2.5V CLOCK + N3004, Motherboard Power Regulation for Computers JAN-10-Y02 1 NIKO-SEM 5 Bit Programmable Synchronous Buck Converter with Dual LDOs N3004 ABSOLUTE MAXIMUM RATINGS PARAMETER 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) VALUE 10V 20V 25°C/W 85°C/W 0 to 70°C -65 to +150°C 0 to +125°C 300°C ELECTRICAL SPECIFICATIONS PARAMETER 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 CONDITIONS SWITCHING SECTION MIN 0.99Vs TYP Vs MAX UNITS 1.01Vs 0.1 0.5 0.4 V % % V V KΩ 115 % 2 27 POWER GOOD SECTION 85 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 Input Bias Current Input Offset Voltage Delay to Output IL = 3mA RL = 5KΩ pull up to 5V SOFT START SECTION CS+ =0V, CS- =5V UVLO SECTION Supply ramping up 0.4 4.8 10 10 0.4 4.3 0.3 10.8 .05 4.5 0.4 2 -2 V V μA V V V V μA mV nS 9.2 0.3 Supply ramping up 4.1 0.2 ERROR COMPARATOR SECTION VDIFF = 10mV 2 +2 100 JAN-10-Y02 NIKO-SEM 5 Bit Programmable Synchronous Buck Converter with Dual LDOs CONDITIONS CURRENT LIMIT SECTION MIN 160 -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 TYP 200 N3004 MAX UNITS 240 +5 2 μA mV % PARAMETER C.S Threshold Set Current C.S Comparator Offset Voltage Hiccup Duty Cycle Operating Supply Current 20 14 60 60 200 220 0.2 V5 100 130 300 mA nS nS nS KHz V V V μA mA Rise Time Fall Time Dead Band Time Oscillator Frequency Oscillator Valley Oscillator Peak VFB1 & VFB2 Input Bias Current IDRIVER1 or IDRIVER2 LINEAR SECTIONS 1.40 1.50 50 1.60 2 Note 1: Vs refers to the set point voltage given in Table 1. PIN CONFIGURATIONS 3 JAN-10-Y02 NIKO-SEM PIN DEFINITIONS Pin # Pin Name 1 CT 5 Bit Programmable Synchronous Buck Converter with Dual LDOs N3004 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. 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 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 VID4 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 VID3 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 VID2 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 VID1 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 VID0 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 2 uH 5V 1000uF + 0.1uF 1000uF x 2 + + 220pF MOSFET P50N02L x 2 2.5uH + 1500uF x 5 + + + + 0.1uF VCORE SBD 1A/30V 10 2.21K 10 470pF 100 10K Short or 5 OHM 1uF + N3004 VCC CS+ HDRV CSLDRV VFB3 LIN1 LIN2 VFB2 VFB1 GND 1K 1K VID 0 VID 1 VID 2 VID 3 VID 4 V12 3.3V VID 0 VID 1 VID 2 VID 3 VID 4 12V + 1uF + 1uF 150pF + 680uF MOSFET P3055LD x 2 100 100 100 0.01uF 0.01uF + 680uF 1.5V GTC BUS SS CT PGD 100 10K 150 + 2.5V CLOCK 220uF 3.3V 10K P.G 0.1uF 6 JAN-10-Y02 NIKO-SEM 5 Bit Programmable Synchronous Buck Converter with Dual LDOs SOIC-20 (DW) MECHANICAL DATA mm mm Min. 0.4 0.23 0.25 0° Typ. N3004 Dimension A B C D E F G Min. 12.6 7.3 10 0.33 Typ. Max. 13.0 7.7 10.65 0.51 Dimension H I J K L M N Max. 1.27 0.32 0.74 8° 1.27 2.1 0.1 2.3 2.5 0.3 7 JAN-10-Y02