ChipFind - документация

Электронный компонент: N3004

Скачать:  PDF   ZIP



1
5 Bit Programmable Synchronous
Buck Converter with Dual LDOs
NIKO-SEM
N3004
JAN-10-Y02
GENERAL DESCRIPTION
The N3004 is a 5 bit TTL-compatible input,
digital-to-analog (DAC) programmable, syn-
chronous 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 pro-
grammability 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.
FEATURES
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













N3004, Motherboard Power Regulation for Computers
SECTION
5V
+
+
ENABLE
+
POWER-GOOD
+
VCORE
VID 0~4
SECTION
12V
2.5V
CLOCK
SWITCHING
+
+
LINEAR
3.3V
1.5V
GTC
BUS



2
5 Bit Programmable Synchronous
Buck Converter with Dual LDOs
NIKO-SEM
N3004
JAN-10-Y02
ABSOLUTE MAXIMUM RATINGS
PARAMETER
VALUE
Supply Voltage (V5 to GND)
10V
Supply Voltage (V12 to GND)
20V
Thermal Resistance Junction to Case,
JC
25C/W
Thermal Resistance Junction to Ambient,
JA
85C/W
Operating Temperature Range
0 to 70C
Storage Temperature Range
-65 to +150C
Junction Operating Temperature
0 to +125C
Lead Temperature (Soldering, 10 Seconds)
300C
ELECTRICAL SPECIFICATIONS
<Unless otherwise specified: V5 = 5V, V12 = 12V and T
A
= 25C>
PARAMETER
CONDITIONS
MIN
TYP
MAX UNITS
SWITCHING SECTION
DAC Output Voltage (Note 1)
0.99Vs
Vs
1.01Vs
V
DAC Output Line Regulation
0.1
%
DAC Output Temp. Variation
0.5
%
VID Input LO
0.4
V
VID Input HI
2
V
VID Input Internal Pull-Up
Resistor to V5
27 K
POWER GOOD SECTION
Power Good Threshold Voltage
85 115
%
Power Good Output LO
I
L
= 3mA
0.4
V
Power Good Output HI
R
L
= 5K
pull up to 5V
4.8 V
SOFT START SECTION
Soft Star Current
CS+ =0V, CS- =5V
10
A
UVLO SECTION
UVLO Threshold for V12
Supply ramping up
9.2
10
10.8
V
UVLO Hysterises for V12
0.3
0.4
.05
V
UVLO Threshold for V5
Supply ramping up
4.1
4.3
4.5
V
UVLO Hysterises for V5
0.2
0.3
0.4
V
ERROR COMPARATOR SECTION
Input Bias Current
2
A
Input Offset Voltage
-2
+2
mV
Delay to Output
V
DIFF
= 10mV
100
nS



3
5 Bit Programmable Synchronous
Buck Converter with Dual LDOs
NIKO-SEM
N3004
JAN-10-Y02
PARAMETER
CONDITIONS
MIN
TYP
MAX UNITS
CURRENT LIMIT SECTION
C.S Threshold Set Current
160
200
240
A
C.S Comparator Offset Voltage
-5
+5
mV
Hiccup Duty Cycle
Css = 0.1F
2
%
SUPPLY CURRENT
Operating Supply Current
CL=3000 pF
V5
20
V12
14 mA
OUTPUT DRIVERS SECTION
Rise Time
C
L
= 3,000pF
60
100
nS
Fall Time
C
L
= 3,000pF
60
130
nS
Dead Band Time
C
L
= 3,000pF
100
200
300
nS
OSCILLATOR SECTION
Oscillator Frequency
C
L
= 150pF
220
KHz
Oscillator Valley
0.2
V
Oscillator
Peak
V5 V
LINEAR SECTIONS
V
FB1
& V
FB2
1.40 1.50 1.60 V
Input Bias Current
2
A
I
DRIVER1
or I
DRIVER2
50 mA
Note 1: Vs refers to the set point voltage given in Table 1.

PIN CONFIGURATIONS



4
5 Bit Programmable Synchronous
Buck Converter with Dual LDOs
NIKO-SEM
N3004
JAN-10-Y02
PIN DEFINITIONS
Pin # Pin Name
Pin Function Description
1 C
T
The oscillator frequency is programmed by connecting an external cap-
acitor from this pin to GND. Operation in range of 50 KHz to 500 KHz.
2 L
IN1
Gate drive output regulator, Linear 1 for GTL+ or Clock supply.
3 V
FB1
Feedback input for L
IN1
.
4 V
FB2
Feedback input for L
IN2
.
5
V5
5V supply voltage.
6 PGD
*
Open collector logic output, high if V
O
within 10% of set point.
7 CS-
Current sense input (Negative), connected to the Source of the power
MOSFET for the core supply.

8

CS+
Current sense input (Positive), connected to the Drain of the power MOS-
FET for the core supply. An external resistor programs the C.S threshold
depending on the R
DS(ON)
of the power MOSFET. An external capacitor is
placed in parallel with the programming resistor to provide high frequency
noise filtering.
9 H
DRV
High side driver output.
10
GND
This pin serves as the ground pin and must be connected directly to the
ground plane. A high frequency capacitor (0.1 to 1F) must be connected
directly from V5 and V12 pins to this pin for noise free operation.
11 L
DRV
Low side driver output.
12
V12
12V supply voltage for LINEAR section. A high frequency capacitor (0.1 to
1F) must be connected directly from this pin to GND pin in order to
supply the peak current to the power MOSFET during the transients.

13

SS
This pin provides the soft start for the switching regulator. An internal
current source charges an external capacitor that is connected from this
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 V
FB3
Feedback input for V
CORE
.
15 VID4
*
Programming input (MSB).
16 VID3
*
Programming
input.
17 VID2
*
Programming
input.
18 VID1
*
Programming
input.
19 VID0
*
Programming input (LSB).
20 L
IN2
Gate drive output regulator, Linear 2 for GTL+ or Clock supply.
*
: All logic level inputs and outputs are open collector TTL compatible.



5
5 Bit Programmable Synchronous
Buck Converter with Dual LDOs
NIKO-SEM
N3004
JAN-10-Y02
OUTPUT SET POINT VOLTAGE vs VID CODES
- Table 1 -
Vs
VID4
VID3
VID2
VID1
VID0
1.30
0 1 1 1 1
1.35
0 1 1 1 0
1.40
0 1 1 0 1
1.45
0 1 1 0 0
1.50
0 1 0 1 1
1.55
0 1 0 1 0
1.60
0 1 0 0 1
1.65
0 1 0 0 0
1.70
0 0 1 1 1
1.75
0 0 1 1 0
1.80
0 0 1 0 1
1.85
0 0 1 0 0
1.90
0 0 0 1 1
1.95
0 0 0 1 0
2.00
0 0 0 0 1
2.05
0 0 0 0 0
2.00
1 1 1 1 1
2.10
1 1 1 1 0
2.20
1 1 1 0 1
2.30
1 1 1 0 0
2.40
1 1 0 1 1
2.50
1 1 0 1 0
2.60
1 1 0 0 1
2.70
1 1 0 0 0
2.80
1 0 1 1 1
2.90
1 0 1 1 0
3.00
1 0 1 0 1
3.10
1 0 1 0 0
3.20
1 0 0 1 1
3.30
1 0 0 1 0
3.40
1 0 0 0 1
3.50
1 0 0 0 0







6
5 Bit Programmable Synchronous
Buck Converter with Dual LDOs
NIKO-SEM
N3004
JAN-10-Y02
APPLICATION CIRCUIT


3.3V
3.3V
+
+
+
+
+
+
+
+
+
+
+
+
+
+
5V
VID 0
VID 4
12V
VID 1
VID 2
VID 3
P.G
100
VFB2
0.1uF
680uF
VID 3
VFB1
10K
VCORE
VID 0
CS+
150
2 uH
HDRV
1uF
10K
P50N02L x 2
1A/30V
P3055LD x 2
100
220uF
1500uF x 5
VID 2
LIN2
100
PGD
1uF
2.5V
CLOCK
0.1uF
CS-
10
1K
470pF
1000uF x 2
LDRV
100
1000uF
SBD
MOSFET
10
N3004
CT
GND
1K
10K
680uF
VID 4
VID 1
LIN1
0.01uF
1.5V
GTC
BUS
220pF
1uF
VCC
2.21K
Short or
5 OHM
VFB3
0.1uF
SS
150pF
100
2.5uH
MOSFET
0.01uF
V12















7
5 Bit Programmable Synchronous
Buck Converter with Dual LDOs
NIKO-SEM
N3004
JAN-10-Y02


































SOIC-20 (DW) MECHANICAL DATA
mm
mm
Dimension
Min. Typ. Max.
Dimension
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
L
F 2.1 2.3 2.5 M
G 0.1 0.3 N