He104man-v8 manual, 6 bus termination (optional) – Tri-M Systems HE104 User Manual
Page 20

23 June 2005
HE104MAN-V8 Manual
Tri-M Engineering
Tel:
800.665.5600, 604.945.9565
1407 Kebet Way, Unit 100
Fax:
604.945.9566
Port Coquitlam, BC V3C 6L3
E-mail:
Canada
Web site:
www.tri-m.com
19
Note: that only the ESR of the output capacitor is used in the formula. It is assumed that the
capacitor is purely resistive at the frequencies about 20kHz. Worst case output ripple is at highest
input voltage. Ripple voltage is independent of load (for continuous mode).
Example
Vout = 5V, Vin = 28V, L1 = 55uH, frequency = 50kNz and three 330uF capacitor with 27 mohm ESR
in parallel.
0.009
•
5
•
(1- (
5
))
Vp –p =
28
55
•
10E6
•
0.5
•
10E5
3.6 Bus Termination (Optional)
AC bus termination is provided by 5 “RC” SOIC packages (3 only for 8-bit PC/104 bus HE 104s),
RC1 to RC5 and discrete components C20 and C27. Each RC package contains 16
resistor/capacitor combinations of 47R and 47PF with a common bus connected to the signal ground.
RC1
RC2
RC3
RC4
RC5
1
GND
GND
GND
GND
GND
2
*SMEMW
IRQ10
*BACK6
SA11
SA3
3
AEN
LA22
SD9
*Refresh
BALE
4
IOCHRDY
IRQ11
DRQ6
SA12
SA4
5
SD0
LA21
*DACK7
DRQ1
IRQ3
6
SD1
LA20
SD11
SA13
SA5
7
SRDY
IRQ15
DRQ7
*DACK1
*DACK2
8
SD2
LA19
SD12
SA14
SA6
9
SD3
LA18
-----
SA15
SA7
10
GND
GND
GND
GND
GND
11
GND
GND
GND
GND
GND
12
SD7
*MEMR
SD15
*IOW
IRQ6
13
SD6
LA17
SD14
SA17
SA9
14
SD5
LA18
SD13
*IOR
IRQ5
15
SD4
IRQ12
SD10
SA16
SA8
16
DRQ2
LA23
SD8
*DACK3
IRQ4
17
SA19
*IOCS16
DRQ5
DRQ3
DA2
18
*SMEMR
*SBHE
*MEMW
IRQ7
SA1
19
SA18
*MEMCS16
*DACK5
SA10
SA0
20
GND
GND
GND
GND
GND
In addition, the following signals are terminated with discrete components.
-
TC C1 (330pF)
-
Reset C20 (330pF)