Description
DS3800HPBD1D1B: Product Overview
The DS3800HPBD1D1B is a daughterboard-grade parallel buffer/decoder that plugs onto a motherboard carrier inside the Mark IV rack. It bi-directionally buffers the 16-bit data bus and 20-bit address bus from the CPU, decodes chip-select and read/write strobes, and routes them to I/O, memory, or communication daughterboards. The card also absorbs VME back-plane surges and provides 1500 V galvanic isolation, ensuring deterministic data transfer even under severe electrical noise typical of turbine decks .
Physical implementation includes 48 TTL buffer ICs, 37 gold-pinned jumpers for address mapping, wait-state insertion, and bus direction control, plus TVS surge suppressors on every line. 20-pin ribbon connectors (input and output) mate with the carrier motherboard; keyed and gold-plated to prevent mis-insertion or fretting corrosion. Front-edge LEDs (red/green) per byte lane give real-time bus activity—no logic analyzer required during commissioning .
Environmental qualification meets IEEE 344 Class 1 (seismic) and –40 °C to +85 °C operation, permitting installation directly on the turbine deck with no extra HVAC. MTBF is >250 000 h at 55 °C, giving >20-year service life in baseload duty .
DS3800HPBD1D1B: Technical Specifications
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Model Number: DS3800HPBD1D1B
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Manufacturer: General Electric (GE Energy)
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Product Type: Parallel Buffer / Decoder Daughterboard
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Data Width: 16-bit bidirectional buffer, 20-bit address decoder
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Buffer Type: TTL 74ALS245-equivalent, sink/source 24 mA
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Isolation: 1500 V AC channel-to-ground, 500 V channel-to-channel
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Jumpers: 37 (address decode, wait-state, bus direction)
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Connectors: 2 × 20-pin ribbon, keyed, gold-plated
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Propagation Delay: <15 ns (buffer), <5 ns skew between lines
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Surge Protection: >500 V TVS on every pin, <1 ns response
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Power Rails: +5 V DC logic, <0.5 W per byte lane
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LEDs: Green = bus active, Red = parity / direction fault
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Temp Range: -40 °C to +85 °C operational, -55 °C to +125 °C storage
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Vibration / Shock: 15 g continuous, 30 g shock (IEEE 344)
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Certifications: SIL2 (IEC 61508), API 670, CE industrial emissions
DS3800HPBD1D1B
Core Features & Customer Value
Deterministic Bus Timing for TMR Voting
<15 ns propagation and <5 ns skew ensure bit-exact congruence across three CPU legs; voter disagreement is <1 ns, mandatory for SIL2 TMR certification and grid-code compliance .
<15 ns propagation and <5 ns skew ensure bit-exact congruence across three CPU legs; voter disagreement is <1 ns, mandatory for SIL2 TMR certification and grid-code compliance .
Hot-Swappable in TMR Strings
Redundant Mark IV allows online replacement of one buffer card; remaining two legs continue voting. MTTR is <5 min—no outage, no load shed, no restart required .
Redundant Mark IV allows online replacement of one buffer card; remaining two legs continue voting. MTTR is <5 min—no outage, no load shed, no restart required .
Field-Configurable Without Software
37 jumpers map I/O addresses, insert wait-states, or disable byte lanes—technician can re-configure for different daughterboards using only a tweaker and the silk-screen legend, eliminating OEM software dependency .
37 jumpers map I/O addresses, insert wait-states, or disable byte lanes—technician can re-configure for different daughterboards using only a tweaker and the silk-screen legend, eliminating OEM software dependency .
Surge-Hardened for Turbine Deck
TVS diodes clamp >500 V spikes from servo drives, contactors, or lightning. 1500 V isolation prevents back-plane flash-over, reducing unplanned replacement by >60 % compared with commercial-grade buffers .
TVS diodes clamp >500 V spikes from servo drives, contactors, or lightning. 1500 V isolation prevents back-plane flash-over, reducing unplanned replacement by >60 % compared with commercial-grade buffers .
Typical Applications
Gas Turbine CPU-to-I/O Bridge
Primary buffer between CPU and DS3800DAC analog output, DS3800HPTG pulse-rate, and DS3800DSWA sequencer cards in Frame 7/9 racks. Deterministic timing guarantees bit-exact voting during start-up, load ramps, and emergency trips .
Primary buffer between CPU and DS3800DAC analog output, DS3800HPTG pulse-rate, and DS3800DSWA sequencer cards in Frame 7/9 racks. Deterministic timing guarantees bit-exact voting during start-up, load ramps, and emergency trips .
Steam Turbine Governor & Auxiliary I/O
Buffers address/data buses to governor servo, lube-oil pressure, and turning-gear I/O modules. Wait-state jumpers slow bus cycle to match slower servo amplifiers, preventing data corruption during transients .
Buffers address/data buses to governor servo, lube-oil pressure, and turning-gear I/O modules. Wait-state jumpers slow bus cycle to match slower servo amplifiers, preventing data corruption during transients .
Black-Start & Emergency Sequencing
Maps emergency battery charger, diesel starter, and breaker-close I/O into CPU memory space during island-mode black-start. Fail-safe decoder defaults to disabled on loss of 5 V, meeting IEC 61508 SIL2 requirements .
Maps emergency battery charger, diesel starter, and breaker-close I/O into CPU memory space during island-mode black-start. Fail-safe decoder defaults to disabled on loss of 5 V, meeting IEC 61508 SIL2 requirements .
