CM8501/A
1.5A BUS TERMINATOR
2002/09/30Rev. 1.1 Champion Microelectronic Corporation Page 1
GENERAL DESCRIPTION
FEATURES
! Patent Filed #6,452,366
! 8-pin PSOP, 16 pin PTSSOP and 16 pin PSOP power
packages
! Source and sink up to 1.5A, no heat sink required
! Peak Current to 3A
! Integrated Power MOSFETs
! Output voltage can be programmed by external resistors
(CM8501)
! Separate voltages for VCCQ and PVDD
! V OUT of ±3% or less at 1.5A
! Minimum external components
! Shutdown for standby or suspend mode operation
! Thermal shutdown protection
! Soft start
The CM8501/A is a low cost switching regulator designed to
provide a desired output voltage or termination voltage for
various applications by converting voltage supplies ranging
from 2.0V to 4.0V. The CM8501 can be implemented to
produce regulated output voltages in two different modes. In
the default mode, when the VIN/2 pin is open, the output
voltage is 50% of the VCCQ. The CM8501 can also be used
to produce various user-defined voltages by forcing a voltage
on the VIN/2 pin. In this case, the output voltage follows the
VIN/2 pin input voltage. The regulated output voltage of
CM8501A is internally set to be 50% of the applied VCCQ.
The switching regulator is capable of sourcing or sinking up to
1.5A of current while regulating an output V TT voltage to
within 3% or less.
The CM8501A could guarantee to provide continuous
sinking or sourcing up to 2A current while enlarging the
layout GND pad dimension as layout suggestion in page
6.
The CM8501/A provides low profile 8-pin PSOP package to
save system space as well as 16-pin PSOP and PTSSOP
packages that are pin-to-pin compatible to the previous
CM8500.
24 Hours Technical Suppor t---WebSIM
Champion provides customers an online circuit simulation tool
called WebSIM. You could simply logon our website at
www.champion-micro.com for details.
APPLICATIONS
! Mother Board
! PCI/AGP Graphics
! Game/ Play Station
! Set Top Box
! IPC
! SCSI-III Bus terminator
! Buck Converter
CM8501/A
1.5A BUS TERMINATOR
2002/09/30Rev. 1.1 Champion Microelectronic Corporation Page 2
PIN CONFIG UR ATION
PSOP-16 (PS16)/PTSSOP-16 (PT16)
Top View
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
VCCA
NC
NC
NC
AGND
SD
VIN/2
AGSEN
NC
PVDD
VL
PGND
NC
VFB
VCCQ
NC
PSOP-8 (PS08)
Top View
1
2
3
4
8
7
6
5
VCCA
VCCQ
AGND
SD
PVDD
VL
PGND
VFB
PIN DESCRIPTION
Pin No. Operating Rating
8501 8501A Symbol Description
Min. Typ. Max. Unit
1 1 VCCA Voltage supply for internal circuits 2 2.5 4 V
2,3,4,9,12,16 -- NC No Connection
5 3 AGND Ground for internal reference voltage divider
6 4 SD Shutdown active high. CMOS input level 0.75 x
VCCA
VCCA
+ 0.3V
V
7 -- VIN/2 Input for external reference voltage VCCQ/2 V
8 --
AGSEN Ground for remote sensing
10 2 VCCQ Voltage reference for external voltage divider 2.5 V
11 5 VFB Feedback node for the VTT VCCQ/2 V
13 6 PGND Ground for output power transistors
14 7 VL Output voltage/inductor connection (IDD1+IDD2,
Output RMS current)
-2.0 +2.0 A
15 8 PVDD Voltage supply for output power transistors 2 2.5 4 V
ORDERING INFORMATION
Part Number Temperature Range Package
CM8501IT -40℃ to 85℃ 16-Pin PTSSOP (PT16)
CM8501IS -40℃ to 85℃ 16-Pin PSOP (PS16)
CM8501AIS -40℃ to 85℃ 8-Pin PSOP (PS08)
CM8501/A
1.5A BUS TERMINATOR
2002/09/30Rev. 1.1 Champion Microelectronic Corporation Page 3
BLOCK DIAGR AM
RAMP AMP
COMPARATOR
THERMO-
PROTECTION
+
-
ERROR AMP
100K
20PF
S
R
Q
Q
OSCILLATOR
RAMP GENERATOR
VCCA
1
VL
7
VCCQ
2
PGND
6
SD
4
100K
+
-
VFB
5
PVDD
8
AGND
3
BLOCK DIAGRAM- 8 PIN
100K
OSCILLATOR/
RAMP GENERATOR
7
VIN/2
100K
14
VL
THERMAL
PROTECTION
11
VFB
RAMP AMP
COMPARATOR
13
PGND
12
NC
9
NC
10
VCCQ
+
-
20PF
ERROR AMP
S
R
Q
Q
5
AGND
3
NC
4
NC
15
PVDD
1
VCCA
+
-
2
NC
6
SD
8
AGSEN
16
NC
BLOCK DIAGRAM- 16 PIN
CM8501/A
1.5A BUS TERMINATOR
2002/09/30Rev. 1.1 Champion Microelectronic Corporation Page 4
APPLIC ATION CIRCUI TS
C2 105
JP3
1
2
3
L1
3.3uH
NOTE:
U1 CM8501
2
1
3
4 5
6
7
8
VCCQ
VCC
AGND
SD FB
PGND
VL
VDD
J1
PWR/IN
1
2
R1
100k
2
1
JP3---->USEING INTERNAL REFERENCE
SOURCE(PIN 1, 2 SHORT)
VDD
R5
0
2 1
C6
220uf/6.3V
TP1
BNC
1
2
3
4
5
U2
CM-431
1 3
2
J2
VTT
1
2
1.5A DDR BUS TERMINATOR DEMO BOARD CIRCUIT
D1
SK12
C5
104
R3
100k
2 1
VCC
C8
10uf/6.3V
JP3---->USEING EXTERNAL REFERENCE
SOURCE(PIN 2,3 SHORT)
R2
1k
2
1
R4
1k
2
1
C3
470
R6
5R1
2
1
VDD VCC
C4 105
JP1
JUMPER
C7
104
JP4 on/off sw
JP2
JUMPER
D2
SK12
J3
VREF-OUT
1
2
C1 100uf/6.3V
8-Pin Schematic
VCC
JP3---->USEING EXTERNAL REFERENCE
SOURCE(PIN 2,3 SHORT)
JP1
JUMPER
C7
104
U1
CM8501
2
1
3
13
14
15
16
4
5
6
7
8 9
10
11
12
NC
VCCA
NC
PGND
VL
PVDD
NC
NC
AGND
SD
VIN/2
AGSEN NC
VCCQ
VFB
NC
R5
0
2 1
C3
470
C9
102
C2 105
D1
SK12
NOTE:
C1 100uf/6.3V
JP4
ON/OFF SW
R6
5R1
2
1
VDD
J1
PWR/IN
1
2
R1
100k
2
1
VDD
JP3---->USEING INTERNAL REFERENCE
SOURCE(PIN 1, 2 SHORT)
JP3
1
2
3
1.5A DDR BUS TERMINATOR DEMO BOARD CIRCUIT
D2
SK12
R4
1k
2
1
C4 105
R3
100k
2 1
J3
VREF-OUT
1
2
JP2
JUMPER
C6
220uf/6.3V
VCC
L1
3.3uH
TP1
BNC
1
2
3
4
5
R2
1k
2
1
U2
CM-431
1 3
2
C8
10uf/6.3V
C5
104
J2
VTT
1
2
16-Pin Schematic
CM8501/A
1.5A BUS TERMINATOR
2002/09/30Rev. 1.1 Champion Microelectronic Corporation Page 5
A BSOLUTE MAXIMUM RATINGS
Junction Temperature ...…………………… …………150°C Absolute maximum ratings are those values beyond which the
device could be permanently damaged. Storage Temperature ……................……. -65°C to 125°C
PVDD/VCCA/VCCQ ......................................….......-0.3V to 4.0V Lead Temperature (Soldering, 5 sec)……………….. 300°C
Voltage on Any Other Pin …………... GND – 0.3V to VCC + 0.3V 16-Pin Package Thermal Resistance (θJA )….. .. .40°C/W
Output RMS Current, Source or Sink .....…………........…...1.5A 8-Pin Package Thermal Resistance (θJA )….….. .50°C/W
OPERATING CONDITIONS
Temperature Range ............................. -40°C to 85°C
PVDD Operating Range .........................2.0V to 4.0V
ELECTRICAL CHARACTERISTICS (Unless otherwise stated, these specifications apply TA=25°C;
VCCA=+3.3V and PVDD=+3.3V) maximum ratings are stress ratings only and functional device operation is not implied.
(Note 1)
CM8501/A
Symbol Parameter Test Conditions
Min. Typ. Max.
Unit
SWITCHING REGULATOR
VCCQ = 2.3V 1.12 1.15 1.18 V
VCCQ = 2.5V 1.22 1.25 1.28 V
IOUT = 0,
Note 2 VCCQ = 2.7V 1.32 1.35 1.38 V
VCCQ = 2.3V 1.09 1.15 1.21 V
VCCQ = 2.5V 1.19 1.25 1.31 V
VL
Output Voltage, SSTL_2 IOUT =
±1.5A,
Note 2
Note 3 VCCQ = 2.7V 1.28 1.35 1.42
V
VCCQ = 2.3V 1.139 1.15 1.162 V
VCCQ = 2.5V 1.238 1.25 1.263 V
VIN/2 Internal Resistor Divider IOUT = 0
Note 2 VCCQ = 2.7V 1.337 1.35 1.364 V
ZIN V
IN/2 Reference Pin Input Impedance Note 2 VCCQ = 0 50 KΩ
fsw Switching Frequency CM8501/A 0.9 1.2 1.5 MHz
IOUT(RMS) Minimum Output RMS Current CM8501/A 1.5 2.0 A
IOUT(PEAK) Maximum Output Peak Current CM8501/A 3 A
OTS Over Temperature Shutdown CM8501/A 135 150 ℃
MOSFETs
RDS(ON) Drain to Source on-State Resistance PVDD=5V 250 mΩ
SUPPLY
IVCCA Quiescent Current VFB = 1.4V
LC unconnected 220 µA
IPVDD VFB = 1.4V
LC unconnected 500 µA
Note 1: Limits are guaranteed by 100% testing, sampling, or correlation with worst case test conditions
Note 2: VCCA, PVDD = 3.3V ±10%, VIN/2=open for CM8501
Note 3: Guaranteed by design, not 100% test
CM8501/A
1.5A BUS TERMINATOR
2002/09/30Rev. 1.1 Champion Microelectronic Corporation Page 6
FUNCTIONAL DESCRIPTION
The CM8501/A is a switching regulator that is capable of
sinking and sourcing 1.5A of current without an external heat
sink. CM8501/A uses a standard surface mount PTSSOP
and PSOP package with bottom metal exposed and the heat
can be piped through the bottom of the device and onto the
PCB.
The CM8501/A integrates power MOSFETs that are capable
of source and sink 1.5A of current while maintaining excellent
voltage regulation. The output voltage can be regulated within
3% or less by using the external feedback. Separate voltage
supply inputs have been added to fit applications with various
power supplies for the databus and power buses.
OUPUTS
The output voltage pins (VL) are tied to the databus, address,
or clock lines via an external inductor. Output voltage is
determined by the VCCQ or VIN/2 inputs for CM8501 and is
determined by the VCCQ only for CM8501A.
INPUTS
The input voltage pins (VCCQ & VIN/2 of CM8501 or VCCQ of
CM8501A) determine the output voltages (VL). At CM8501,
when the VIN/2 pin is open, the output voltage is 50% of the
VCCQ input. If a specific voltage is forced at the VIN/2 pin, the
output voltage follows the voltage at the VIN/2 pin. At CM8501A,
the output voltage is always 50% of the VCCQ input.
VCCQ is suggested to connect to VCCQ of memory module for
better tracking with memory VCCQ.
OTHER SUPPLY VOLTAGES
Several inputs are provided for the supply voltages: PVDD and
VCCA
The PVDD provide the power supply to the power MOSFETs.
VCCA provide the voltage supply to the logic section and
internal error amplifiers of CM8501/A.
FEEDBACK
The VFB pin is an input that can be used for closed loop
compensation. This input is derived from the voltage output.
AGSEN pin is a contact node of internal resistor divider for
remote sense (CM8501).
CM8501/A
1.5A BUS TERMINATOR
2002/09/30Rev. 1.1 Champion Microelectronic Corporation Page 7
Suggested La yout GND Pad Dimension: to guarantee providing continuous sinking or sourcing current
up to 2A.
PSOP-08 Bottom GND Pad Package
2.34 X 2.92 mm
Package Bottom View
Layout GND Pad Package
Land Pattern Comp Side
Solder Mask GND Pad Package
2.4 X 3.0 mm
Solder Mask Comp Side
CM8501/A
1.5A BUS TERMINATOR
2002/09/30Rev. 1.1 Champion Microelectronic Corporation Page 8
PACKAGE DIMENSIO N
8-PIN PSOP (PS08)
θ
θ
CM8501/A
1.5A BUS TERMINATOR
2002/09/30Rev. 1.1 Champion Microelectronic Corporation Page 9
PACKAGE DIMENSIO N
16-PIN PTSSOP (PT16)
θ
θ
16-PIN PSOP (PS16)
θ
θ
CM8501/A
1.5A BUS TERMINATOR
2002/09/30Rev. 1.1 Champion Microelectronic Corporation Page 10
IMPORTANT NOTICE
Champion Microelectronic Corporation (CMC) reserves the right to make changes to its products or to discontinue
any integrated circuit product or service without notice, and advises its customers to obtain the latest version of
relevant information to verify, before placing orders, that the information being relied on is current.
A few applications using integrated circuit products may involve potential risks of death, personal injury, or severe
property or environmental damage. CMC integrated circuit products are not designed, intended, authorized, or
warranted to be suitable for use in life-support applications, devices or systems or other critical applications. Use of
CMC products in such applications is understood to be fully at the risk of the customer. In order to minimize risks
associated with the customer’s applications, the customer should provide adequate design and operating
safeguards.
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