CM8501C
1.5A BUS TERMINATOR
2002/09/30 Rev. 1.0 Champion Microelectronic Corporation Page 1
GENERAL DESCRIPTION
FEATURES
! Patent Filed #6,452,366
! 8-pin SOP 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
! 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 CM8501C 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 4.5V. The CM8501C 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 CM8501C 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
CM8501C 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 CM8501C provides low profile 8-pin PSOP package to
save system space.
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
PIN CONFIG UR ATION
SOP-8 (S08)
Top View
1
2
3
4
8
7
6
5
VCCA
VCCQ
AGND
SD
PVDD
VL
PGND
VFB
CM8501C
1.5A BUS TERMINATOR
2002/09/30 Rev. 1.0 Champion Microelectronic Corporation Page 2
PIN DESCRIPTION
Operating Rating
Pin No. Symbol Description Min. Typ. Max. Unit
1 VCCA Voltage supply for internal circuits 2.0 4.5 V
3 AGND Ground for internal reference voltage divider
4 SD Shutdown active high. CMOS input level 0.75 x
VCCA
VCCA
+ 0.3V
V
2 VCCQ Voltage reference for external voltage divider 2.5 V
5 VFB Feedback node for the VTT VCCQ/2 V
6 PGND Ground for output power transistors
7 VL Output voltage/inductor connection (IDD1+IDD2,
Output RMS current)
-1.5 +1.5 A
8 PVDD Voltage supply for output power transistors 2.0 4.5 V
ORDERING INFORMATION
Part Number Temperature Range Package
CM8501CIS -40℃ to 85℃ 8-Pin SOP (S08)
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
CM8501C
1.5A BUS TERMINATOR
2002/09/30 Rev. 1.0 Champion Microelectronic Corporation Page 3
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
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 4.5V Lead Temperature (Soldering, 5 sec)……………….. 300°C
Voltage on Any Other Pin ………... GND – 0.3V to VCC + 0.3V Thermal Resistance (θJA )….. ……………….. .100°C/W
Output RMS Current, Source or Sink .....…………........…...1.5A
OPERATING CONDITIONS
Temperature Range ............................. -40°C to 85°C
PVDD Operating Range .........................2.0V to 4.5V
CM8501C
1.5A BUS TERMINATOR
2002/09/30 Rev. 1.0 Champion Microelectronic Corporation Page 4
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)
CM8501C
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 CM8501C 1.2 MHz
IOUT(RMS) Minimum Output RMS Current CM8501C 1.5 2.0 A
IOUT(PEAK) Maximum Output Peak Current CM8501C 3 A
OTS Over Temperature Shutdown CM8501C 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%
Note 3: Guaranteed by design, not 100% test
CM8501C
1.5A BUS TERMINATOR
2002/09/30 Rev. 1.0 Champion Microelectronic Corporation Page 5
FUNCTIONAL DESCRIPTION
The CM8501C is a switching regulator that is capable of
sinking and sourcing 1.5A of current without an external heat
sink.
The CM8501C 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 and is determined by the VCCQ.
INPUTS
The input voltage pins (VCCQ) determine the output voltages
(VL). At CM8501C, 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 CM8501C.
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.
PACKAGE DIMENSIO N
8-PIN SOP (S08)
PIN 1 ID
θ
θ
CM8501C
1.5A BUS TERMINATOR
2002/09/30 Rev. 1.0 Champion Microelectronic Corporation Page 6
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.
HsinChu Headquarter Sales & Marketing
5F, No. 11, Park Avenue II,
Science-Based Industrial Park,
HsinChu City, Taiwan 300
11F, No. 306-3, Sec. 1, Ta Tung Rd.,
Hsichih, Taipei Hsien,
Taiwan 221
T E L : +886-3-567 9979 T E L : +886-2-8692 1591
FAX: +886-3-567 9909 F A X : +886-2-8692 1596
http://www.champion-micro.com
