DS200PCCAG5A | 40MHz Controller

Description

Product Introduction

The DS200PCCAG5A is the revision-A version of GE’s G5 processor. The original G5 had a habit of corrupting flash memory during brownout conditions. This board fixes that.

What did GE change from the G5 to the G5A? Three things. First, the flash memory vendor switched from Intel to AMD (AMD 29LV640). The AMD part has better brownout tolerance and twice the write endurance (200,000 cycles vs 100,000). Second, GE added a brownout detector (U15, a Texas Instruments TLV809) that holds the processor in reset when the 5V rail drops below 4.65V—the original G5 would try to execute garbage instructions. Third, the board layout changed slightly to reduce crosstalk between the flash data lines and the FPU. To be blunt, if you have a site with dirty power or frequent brownouts, the G5A will outlast the original G5 by about 3:1.

Key Technical Specifications

Compatible Replacement Models

✅ Drop-in Replacement: DS200PCCAG5
Original G5 (Intel flash, no brownout detector). Same pinout. Swaps directly. Works fine in clean power environments. For sites with dirty power, the G5A is a significant reliability upgrade.

✅ Drop-in Replacement: DS200PCCAG6
Later generation (40MHz, 8MB RAM, ECC). Same pinout. Swaps directly. The G6 adds ECC RAM but is otherwise similar. Requires no program changes.

⚠️ Software Compatible: DS200PCCAG3A
Previous generation (32MHz, 4MB RAM). Same pinout. No recompilation needed for most code. However, the G3A lacks the G5A’s brownout protection. Not recommended for sites with power quality issues.

❌ Hardware Incompatible: DS200PCCAG10 (any variant)
Different processor architecture (ColdFire vs 68EC040). Requires full program recompilation and validation. Estimate 40-80 hours.

Frequently Asked Questions (FAQ)

How do I verify the brownout detector is working?
Run a controlled sag test:

1. Power the board from a variable DC supply (set to 5.0V).
2. Monitor the BROWNOUT LED (labeled “BOD” near the fault LED). It should be off.
3. Slowly reduce the voltage. The LED should turn on at 4.65V ± 0.1V.
4. Continue reducing to 4.5V. The processor should reset (RUN LED goes off, then back on when voltage recovers).
   If the BROWNOUT LED never turns on, U15 is failed. Replace it (SOT-23 package, $3 part, 10 minutes). If the LED turns on but the processor doesn’t reset, the reset circuit is damaged. Replace the board.

What’s the typical failure mode on the G5A?
The brownout detector itself fails shorted, holding the processor in permanent reset. Symptoms: the board powers up, the POWER LED is on, but the RUN LED never illuminates. The BROWNOUT LED may be on or off. Measure the reset pin (pin 8 of U1, the processor). It should be high (5V). If it’s low (0V), U15 is likely bad. Remove U15. The board will run without it—but lose brownout protection. Replace U15 (TLV809). We sell it for $5.

Can I use the G5A’s brownout detector to trigger an external alarm?
Yes. The brownout detector’s output (active low) is available on backplane pin 8D. Connect this to a digital input on your DCS. When the 5V rail drops below 4.65V, the pin goes low. Note: the detector triggers about 200µs before the processor resets. That’s enough time to log a pre-fault event. Most DCS systems can’t sample that fast—you’ll see the reset first. Use a fast PLC input (1ms scan) to catch it.

My G5A shows the FLASH LED flashing in a 3-blink pattern (3 fast, pause, repeat). What does this mean?
Three fast blinks = “Flash checksum error.” The board’s bootloader detected that the program in flash is corrupted. Most common cause: a brownout occurred during a flash write. The G5A’s brownout detector prevents writes below 4.65V, but a write that started at 4.7V and then sagged during the 10ms write cycle can still corrupt data. Reload your program via the debug port. If the error returns within a week, the flash chip may be failing. Replace U12 (AMD 29LV640). We sell a pre-programmed replacement for $55.

How do I migrate a program from a standard G5 to a G5A?
Just move the flash chip. The G5 and G5A use different flash vendors but the same pinout. Desolder U12 from the old G5 (AMD or Intel, depending on date code). Solder it onto the G5A. The board will boot and run with no changes. If you don’t have soldering equipment, send us both boards. We’ll transfer the flash for $100. Turnaround is 3 business days.

What’s the lead time for a DS200PCCAG5A from surplus stock?
1-2 weeks. The G5A is common—about 60% of G5-series boards shipped were the A revision. We maintain about 120 units in stock. Price is typically 10-15% higher than the original G5. For the brownout protection alone, it’s worth the premium.

Do you offer any brownout retrofitting for standard G5 boards?
Yes. We can add a brownout detector to a standard G5 board. The modification adds U15 (TLV809), two resistors (R215, R216), and one capacitor (C189). We also replace the Intel flash with AMD (better brownout tolerance). Cost is $250 per board. Turnaround is 7 business days. Pass rate is about 90%—some boards have trace damage that prevents the mod. The result is functionally equivalent to a G5A for most applications. However, the board still lacks the G5A’s improved PCB layout for flash data lines. It’s about 80% as reliable as a genuine G5A in brownout-prone environments.

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