概述
数据手册CM8500AIS 概述
3A BUS TERMINATOR 3A总线端接
CM8500AIS 数据手册
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PDF下载CM8500A
3A BUS TERMINATOR
GENERAL DESCRIPTION
FEATURES
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Patent Filed #6,452,366
pin PTSSOP and PSOP package
The CM8500A is a switching regulator designed to provide a
desired output voltage or termination voltage for various
applications by converting voltage supplies ranging from 2.0V
to 5.0V. The CM8500A can be implemented to produce
regulated output voltages in two different modes. In the
Source and sink up to 3A, no heat sink required
Peak Current to 6A
Integrated Power MOSFETs
Output voltage can be programmed by external resistors
Separate voltages for VCCQ and PVDD
V OUT of ±3% or less at 3A
default mode, when the VIN/2 pin is open, the output voltage
is 50% of the VCCQ. The CM8500A can also be used to
Minimum external components
produce various user-defined voltages by forcing a voltage on
the VIN/2 pin. In this case, the output voltage follows the
Shutdown for standby or suspend mode operation
Thermal shutdown protection
VIN/2 pin input voltage. The switching regulator is capable of
sourcing or sinking up to 3A of current while regulating an
output V TT voltage to within 3% or less.
6A Low Noise Current Limit Protection
External Soft Start
Rail to Rail output Buck Converter
The CM8500A, used in conjunction with series termination
resistors, provides an excellent voltage source for active
termination schemes of high speed transmission lines as
those seen in high speed memory buses and distributed
backplane designs.
APPLICATIONS
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Mother Board
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PCI / AGP Graphics
Game / Play Station
Set Top Box
The voltage output of the regulator can be used as a
termination voltage for other bus interface standards such as
SSTL, CMOS, Rambus ™ ,GTL+, VME, LV-CMOS, LV-TTL,
and PECL.
IPC
SCSI-III Bus terminator
Buck Converter
PIN CONFIGURATION
PSOP-16 (PS16)/PTSSOP-16 (PT16)
Top View
1
2
3
4
5
6
7
8
VCC2
PVDD2
VL2
16
15
14
13
12
11
10
9
VCC1
PVDD1
VL1
PGND2
AGND
VFB
PGND1
AGND
SD
VIN/2
AGSEN
VCCQ
AGND
2008/01/16
Champion Microelectronic Corporation
Page 1
CM8500A
3A BUS TERMINATOR
PIN DESCRIPTION
Pin No.
Symbol
Description
Operating Rating
Min.
2
Typ.
Max.
Unit
V
1,16
2,15
3,14
VCC1,VCC2
PVDD1,PVDD2
VL1,VL2
Voltage supply for internal circuits
Voltage supply for output power transistors
Output voltage/inductor connection
(IDD1+IDD2, Output RMS current)
Ground for output power transistors
Ground for internal reference voltage divider
Ground for remote sensing
2.5
5
5
3
2
2.5
V
-3
A
4,13
PGND1,PGND2
AGND
5,9,12
8
6
AGSEN
SD
Shutdown active high. CMOS input level
0.75 X
VCC
0
VCC +
0.3V
VIN
5
V
7
VIN/2
VCCQ
VFB
Input for external reference voltage
Voltage reference for external voltage divider
Feedback node for the VTT
V
V
V
10
11
5
BLOCK DIAGRAM
VCC1
PVDD2
15
SD
6
PVDD1
2
VCCQ
10
VCC2
16
1
OSCILLATOR/
RAMP GENERATOR
3
VL1
VL2
14
S
R
Q
Q
100K
-
+
ERROR AMP
+
-
VIN/2
AGND
AGND
RAMP AMP
COMPARATOR
7
5
100K
9
20PF
12
AGND
13
PGND2
4
PGND1
11
8
AGND
VFB
ORDERING INFORMATION
Part Number
Temperature Range
Package
-40℃ to 85
CM8500AIT
16-Pin PTSSOP (PT16)
16-Pin PSOP (PS16)
16-Pin PTSSOP (PT16)
16-Pin PSOP (PS16)
Evaluation Board (T16)
-40℃ to 85
-40℃ to 85
-40℃ to 85
CM8500AIS
CM8500AGIT*
CM8500AGIS*
CM8500ATEVAL
*Note: G : Suffix for Pb Free Product
2008/01/16
Champion Microelectronic Corporation
Page 2
CM8500A
3A BUS TERMINATOR
ABSOLUTE MAXIMUM RATINGS
Absolute maximum ratings are those values beyond which the
device could be permanently damaged.
Junction Temperature ...…………………… ……………150°C
Storage Temperature
……................……. -65°C to 125°C
PVDD/VCC/VCCQ ......................................….......-0.3V to 6.0V
Lead Temperature (Soldering, 5 sec)………………….. 260°C
Thermal Resistance(θJA )….. …………..…………….. .40°C/W
Voltage on Any Other Pin ………... GND – 0.3V to VCC + 0.3V
Output RMS Current, Source or Sink .....…………........…...3.0A
OPERATING CONDITIONS
Temperature Range ............................. -40°C to 85°C
PVDD Operating Range .........................2.0V to 5.0V
ELECTRICAL CHARACTERISTICS (Unless otherwise stated, these specifications apply
TA=25°C; VCC=+3.3V and PVDD=+3.3V) maximum ratings are stress ratings only and functional device operation is not implied.(Note
1)
CM8500A
Symbol
Parameter
Test Conditions
Unit
Min.
Typ.
Max.
SWITCHING REGULATOR
IOUT = 0, VCCQ = 2.3V
1.12
1.22
1.15
1.25
1.18
1.28
V
V
V
VIN/2 =
open
VCCQ = 2.5V
VCCQ = 2.7V
1.32
1.35
1.38
Note 2
VL
Output Voltage, SSTL_2
IOUT = VCCQ = 2.3V
1.09
1.19
1.15
1.25
1.21
1.31
V
V
±3A,
VIN/2 =
open
VCCQ = 2.5V
VCCQ = 2.7V
1.28
1.35
1.42
V
Note 3
VCCQ = 2.3V
VCCQ = 2.5V
VCCQ = 2.7V
VCCQ = 0
1.139
1.238
1.337
1.15
1.25
1.35
50
1.162
1.263
1.364
V
V
IOUT = 0
Note 2
VIN/2
Internal Resistor Divider
V
KΩ
ZIN
fsw
VIN/2 Reference Pin Input Impedance
Switching Frequency
Note 2
CM8500A
480
660
3
KHz
A
IOUT(RMS)
IOUT(PEAK)
Ilimit
Maximum Output RMS Current
Maximum Output Peak Current
Current limit
CM8500A
CM8500A
CM8500A
6
A
6
A
MOSFETs
RDS(ON)
SUPPLY
mΩ
Drain to Source on-State Resistance
Quiescent Current
PVDD=5V
150
180
VFB = 1.4V
LC unconnected
VFB = 1.4V
IVCCA
200
500
µA
µA
IPVDD
LC unconnected
Note 1: Limits are guaranteed by 100% testing, sampling, or correlation with worst case test conditions
Note 2: VCC, PVDD = 3.3V ±10%
Note 3: It’s not 100% test
2008/01/16
Champion Microelectronic Corporation
Page 3
CM8500A
3A BUS TERMINATOR
FUNCTIONAL DESCRIPTION
The CM8500A is a switching regulator that is capable of
sinking and sourcing 3A of current without an external heat
Low Noise Current Limit:
CM3708A’s current limit is a low noise current limit. It increase
the system loop noise immunity while it is doing the current limit
protection for the system. The current limit is around 6A for the
normal 3A operation.
sink.
CM8500A 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.
INPUTS
The CM8500A integrates power MOSFETs that are capable
of source and sink 3A of current while maintaining excellent
The input voltage pins (VCCQ or VIN/2) determine the output
voltages (VL1 or VL2). In the default mode, when the VIN/2 pin
voltage regulation. The output voltage can be regulated within is open, the output voltage is 50% of the VCCQ input.
3% or less by using the external feedback. Separate voltage If a specific voltage is forced at the VIN/2 pin, the output voltage
supply inputs have been added to fit applications with various follows the voltage at the VIN/2 pin. VCCQ suggested
power supplies for the databus and power buses.
connecting to VCCQ of memory module for better tracking with
memory VCCQ.
VREF
The reference voltage could be ranged from 0V to VIN.
OTHER SUPPLY VOLTAGES
Several inputs are provided for the supply voltages: PVDD1,
PVDD2, VCC1, and VCC2.
OUPUTS
The output voltage pins (VL1, VL2) are tied to the databus,
address, or clock lines via an external inductor. Output voltage
is determined by the VCCQ or VIN/2 inputs so it can be from
0V to VIN..
The PVDD1 and PVDD2 provide the power supply to the power
MOSFETs. VCC1 and VCC2 provide the voltage supply to the
logic section and internal error amplifiers.
Internal Power Switches:
FEEDBACK
CM3708A has been integrated 2 Power MOSFETs whose
RDS(ON) is around 100m Ohm each.
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.
APPLICATIONS
USING THE CM8500A FOR SSTL BUS
TERMINATION
Figure 1 is the typical schematic of the CM8500ATEVAL that
shows the recommended approach for bus terminating
solutions for SSTL-2 bus. This circuit can be used in PC
memory and Graphics memory applications as shown in
Figure 2 and Figure 3.
Figure 4 shows the PCB layout of the CM8500ATEVAL.
Table 1details the key parameters of SSTL_2 specification.
Figure 5 shows two different approach of SSTL_2 Terminated
Output. (Refer to page 8 for detail description.)
2008/01/16
Champion Microelectronic Corporation
Page 4
CM8500A
3A BUS TERMINATOR
APPLICATION CIRCUIT
NOTE:
J3:referance output provided from Vtt
J4:short :Demo kit on .
open:off(into shutdown mode)
J6:reference output provided from shunt regulator
J5:pin1 ,pin2 short:Vtt = 1/2Vcc
Vref-OUT
J3
1
2
C13
104
When external voltage applied ,pin1,2 should be open
and pin2:connect to external voltage (+)
pin3:connect to external voltage (-)
Vtt=1/2 external voltage
R8
100
TP1
BNC
4
3
1
D6
SK12
L1
3.3uH
R6,R7(option circuit)forVttVOLTAGEADJUST
Vtt=(Vcc*R6)/R6+R7
100uf /6.3V
100uf /6.3V 820uf /6.3V
D5
SK12
VTT
J1
C12
C11
C7
1
2
C3
104
C2
104
C15
10uf /6.3V
VCC
R1
5R1
J2
U1 CM8500A
VCC
VDD
DC-INPUT
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
VCC1
VCC2
VDD2
VL2
1
2
VDD
VDD
VDD1
VL1
C14
C16
470uf /6.3V
2
1
100uf/6.3V
C5
C1
104
C10
10uf/6.3V
C4
104
R5
100k
104
C9
PGND1 PGND2
AGND1 AGND4
100uf /6.3V
SD
FB
J5
3
1
J4ON/OFF
R6
2
2
1
2
1
2/VCC
VCCQ
R7
C6
102
IN/EXT
G-sense AGND3
10k
10k
R3 200k
1
2
1
2
R4
1k
C8
102
Figure 1 . CM8500A Typical Application
(Schematic of CM8500A TEVAL)
2008/01/16
Champion Microelectronic Corporation
Page 5
CM8500A
3A BUS TERMINATOR
Figure 2. Termination Solution for PC Main Memory (Mother Boards)
Figure 3. Termination Solution for Graphic Memory (AGP Graphics)
2008/01/16
Champion Microelectronic Corporation
Page 6
CM8500A
3A BUS TERMINATOR
CM8500ATEVAL PART LIST
Item
Q’ty
Description
Designator
Manufacturer
Resistors
0805, 5Ω, 1/8W
1
2
3
4
5
1
1
1
1
2
R1
0805, 100Ω, 1/8W
0805, 470Ω, 1/8W
0805, 1KΩ, 1/8W
0805, 100KΩ, 1/8W
R8
R9 (option)
R4
R3, R5
Capacitors
6
1
6
1
1
2
4
0805, 1nF/ 16V (102)
C6, C8
7
0805, 0.1µF/ 16V (104)
C1, C2, C3, C4, C5
C13
8
0805, 1µF/ 16V (105)
CE 10φ, 820uF/ 6.3V
9
C7
Sanyo OSCON
10
11
B Size, Tant 10uF/ 6.3V
D Size, Tant 100uF/ 6.3V
C10, C15
C9, C11, C12, C14
Magnetics
12
1
3.3uH 5A Inductor
L1
Bipolar Electronic Corp.
IC’s
1
13
14
CM8500AIT
CM431L
U1
Champion Microelectronic Corp.
Champion Microelectronic Corp.
1
U2 (option)
Connectors
15
16
17
1
2-pin, 2.54mm
J2
4
2-pin Jumper, 2.54mm
3-pin Jumper, 2.54mm
J1, J3, J4, J6 (option)
J5
1
PCBs
18
1
CM8500ATEVAL PCB
Champion Microelectronic Corp.
Vendor Information
Bipolar Electronic Corp.
Sanyo
Phn: +886-3-360 8892
2008/01/16
Champion Microelectronic Corporation
Page 7
CM8500A
3A BUS TERMINATOR
CM8500ATEVAL PCB LAYOUT
Figure 4. CM8500AEVAL PCB Layout
SSTL-2 SPECIFICATIONS
SYMBOL
PARAMETER
MIN
VDDQ
TYP
MAX
N/A
UNITS
VDD
Device Supply Voltage
Output Supply Voltage
Input Reference Voltage
Termination Voltage
V
V
V
V
VDDQ
VREF
VTT
2.3
2.5
2.7
1.15
1.25
VREF
1.35
VREF - 0.04
VREF + 0.04
INPUT DC LOGIC LEVELS
VIH (DC)
VIL (DC)
DC Input Logic High
DC Input Logic Low
VREF + 0.18
- 0.3
VDDQ + 0.3
VREF - 0.18
V
V
INPUT AC LOGIC LEVELS
VIH (AC)
VIL (AC)
AC Input Logic High
AC Input Logic Low
VREF + 0.35
V
V
VREF - 0.35
OUTPUT DC CURRENT DRIVE
IOH (DC)
IOL (DC)
Output Minimum Source DC Current
- 15.2
15.2
mA
mA
Output Minimum Sink DC Current
Notes:
VREF and VTT must track variations in VDDQ
Peak-to-peak AC noise on VREF may not exceed ±2% VREF (DC)
VTT of transmitting device must track VREF of receiving device
Table 1. Key Specifications for SSTL_2
2008/01/16
Champion Microelectronic Corporation
Page 8
CM8500A
3A BUS TERMINATOR
SSTL_2 TERMINATED OUTPUT
Single Terminated Output
Double Terminated Output
Figure 5. SSTL_2 Terminated
Output
Note.
The SSTL_2 specification requires adequate output current drive so that parallel termination schemes can be used. The use
of parallel termination is important for high-speed signaling, since it allows proper termination of the bus transmission lines,
which reduces signal reflections. The result will be improved settling, lower EMI emissions, and higher possible clock rates. A
termination resistance of 23Ω to V can be used and still comply with the minimum output voltages and output
minimum
TT
currents of the
SSTL_2 specification.
Two choices for implementing the parallel termination are shown in Figure 5.
Double Terminated Output
The bus is terminated at both ends with a 50Ω resistor, for a combined parallel resistance of 25Ω.
Single Terminated Output
The bus is terminated at the far end from the controller with a single 25Ω resistor.
It is strongly recommended that the single resistor termination scheme be used for best performance. The benefits of this
approach include reduced cost, simpler signal routing, reduced reflections, and better signal bandwidth and settling.
2008/01/16
Champion Microelectronic Corporation
Page 9
CM8500A
3A BUS TERMINATOR
CM8500AEVAL TESTING DIAGRAM
Figure 6. CM8500AEVAL Typical Testing Diagram
TYPICAL CHARACTERISTICS
CM8500 Temperature vs. VTT (VCC,VCCQ&VDD=3.3V)
1.350
1.300
1.250
1.200
1.150
1A
2A
3A
-40
-30
-20
-10
0
10
20
30
40
50
60
70
80
85
T(
℃
)
Temperature vs. VTT VCC, VCCQ & VDD=3.3V
2008/01/16
Champion Microelectronic Corporation
Page 10
CM8500A
3A BUS TERMINATOR
CM8500 Temperature vs. VTT (VCC,VCCQ&VDD=2.5V)
1.350
1.300
1.250
1.200
1.150
1A
2A
3A
-40
-30
-20
-10
0
10
20
30
40
50
60
70
80
85
T(
℃
)
Temperature vs. VTT VCC, VCCQ & VDD=2.5V
2V INPUT
LOAD: 0A - 3A
2V INPUT
LOAD: 3A - 0A
2.5V INPUT
LOAD: 0A - 3A
2.5V INPUT
LOAD: 3A - 0A
3.3V INPUT
LOAD: 0A - 3A
3.3V INPUT
LOAD: 3A - 0A
2008/01/16
Champion Microelectronic Corporation
Page 11
CM8500A
3A BUS TERMINATOR
PACKAGE DIMENSION
16-PIN PTSSOP (PT16)
16-PIN PSOP (PS16)
θ
2008/01/16
Champion Microelectronic Corporation
Page 12
CM8500A
3A BUS TERMINATOR
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.
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
provide adequate design and operating safeguards.
CMC integrated circuit products are not designed, intended,
with
the
customer’s
applications,
the
customer
should
HsinChu Headquarter
Sales & Marketing
5F, No. 11, Park Avenue II,
Science-Based Industrial Park,
HsinChu City, Taiwan 300
7F-6, No. 32, Sec. 1, Chenggong Rd.,
Nangang District , Taipei City 115 Taiwan
TEL: +886-3-567 9979
T E L : +886-2-2788 0558
F A X : +886-2-2788 2985
FAX: +886-3-567 9909
http://www.champion-micro.com
2008/01/16
Champion Microelectronic Corporation
Page 13
CM8500AIS 相关器件
| 型号 | 制造商 | 描述 | 价格 | 文档 |
| CM8500AIT | CHAMP | 3A BUS TERMINATOR | 获取价格 |
|
| CM8500ATEVAL | CHAMP | 3A BUS TERMINATOR | 获取价格 |
|
| CM8501 | CHAMP | 1.5A BUS TERMINATOR | 获取价格 |
|
| CM8501A | CHAMP | 1.5A BUS TERMINATOR | 获取价格 |
|
| CM8501AGIS | CHAMP | 1.5A BUS TERMINATOR | 获取价格 |
|
| CM8501AIS | CHAMP | 1.5A BUS TERMINATOR | 获取价格 |
|
| CM8501C | CHAMP | 1.5A BUS TERMINATOR | 获取价格 |
|
| CM8501CGIS | CHAMP | 1.5A BUS TERMINATOR | 获取价格 |
|
| CM8501CIS | CHAMP | 1.5A BUS TERMINATOR | 获取价格 |
|
| CM8501GIS | CHAMP | 1.5A BUS TERMINATOR | 获取价格 |
|
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