Tri-M Systems HE104 - 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: [email protected]
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)