Instrustar ISDS205A
| Status | in progress |
|---|---|
| Channels | 2 |
| Samplerate | 48MHz |
| Analog bandwidth | 20MHz |
| Vertical resolution | 8bit |
| Triggers | none (SW-only) |
| Input impedance | 1MΩ‖25pF |
| Memory | none |
| Display | none |
| Connectivity | USB |
| Website | instrustar.com |
The Instrustar ISDS205A is a USB-based, 2-channel oscilloscope with an analog bandwidth of 20MS/s and 48MS/s sampling rate.
See Instrustar ISDS205A/Info for more details (such as lsusb -v output) on the device.
Hardware
- Cypress FX2LP CY7C68013AC (USB 2.0 HS controller)
- Analog Devices AD9288 (ADC)
- Microchip 24LC64I (64K I²C EEPROM)
- (2)NXP 74HC4051 (8-Channel Analog Mux)
- NXP 74HC595D (8bit Shift Register (Serial-in to Serial or Parallel-out))
- Oscillator GZX24.000 (24MHz crystal)
- (4) Huike (Shenzhen) HK23F-DC5V-SHG (Reed switch)
Cypress FX2 pinout:
| PD5 | 1- | O | -56 | PD4 |
| PD6 | 2- | -55 | PD3 | |
| PD7 | 3- | -54 | PD2 | |
| GND | 4- | -53 | PD1 | |
| CLKOUT | 5- | -52 | PD0 | |
| VCC | 6- | -51 | *WAKEUP | |
| GND | 7- | -50 | VCC | |
| RDY0/*SLRD | 8- | -49 | RESET# | |
| RDY1/*SLWR | 9- | -48 | GND | |
| AVCC | 10- | -47 | PA7 | |
| (24MHz crystal) XTALOUT | 11- | -46 | PA6 (74HC595D, SHCP) | |
| (24MHz crystal) XTALIN | 12- | -45 | PA5 (74HC595D, STCP) | |
| AGND | 13- | -44 | PA4 (74HC595D, DS) | |
| AVCC | 14- | -43 | PA3 | |
| (USB D+) DPLUS | 15- | -42 | PA2 | |
| (USB D-) DMINUS | 16- | -41 | PA1 | |
| AGND | 17- | -40 | PA0 (1kHz scope cal pin) | |
| VCC | 18- | -39 | VCC | |
| GND | 19- | -38 | CTL2 | |
| (CTL0, AD9288 ENCA/B) *IFCLK | 20- | -37 | CTL1 | |
| RESERVED | 21- | -36 | CTL0 (IFCLK, AD9288 ENCA/B) | |
| (EEPROM SCL) SCL | 22- | -35 | GND | |
| (EEPROM SDA) SDA | 23- | -34 | VCC | |
| VCC | 24- | -33 | GND | |
| PB0 | 25- | -32 | PB7 | |
| PB1 | 26- | -31 | PB6 | |
| PB2 | 27- | -30 | PB5 | |
| PB3 | 28- | -29 | PB4 |
NXP 74HC595D pinout:
| (upper 74HC4051D, S0) Q1 | 1- | O | -16 | VCC |
| (lower 74HC4051D, S0) Q2 | 2- | -15 | Q0 (upper 74HC4051D, S1) | |
| (lower 74HC4051D, S1) Q3 | 3- | -14 | DS (FX2 PA4) | |
| Q4 | 4- | -13 | OE# (GND) | |
| Q5 | 5- | -12 | STCP (FX2 PA5) | |
| Q6 | 6- | -11 | SHCP (FX2 PA6) | |
| Q7 | 7- | -10 | MR# (VCC) | |
| GND | 8- | -9 | Q7S |
NXP 74HC4051D (upper/lower, CH1/CH2) pinout:
|
|
Microchip 24LC64I pinout:
| (VCC) A0 | 1- | O | -8 | VCC |
| (GND) A1 | 2- | -7 | WP (GND) | |
| (GND) A2 | 3- | -6 | SCL (FX2 SCL) | |
| VSS | 4- | -5 | SDA (FX2 SDA) |
Analog Devices ADS9288 pinout:
| AD9288 pins | Description |
|---|---|
| S1, S2 | S1=VCC, S2=GND. "Normal operation, data align disabled". |
| DFS | Tied to GND. Data format select = "offset binary" (not "twos complement"). |
| AINA, AINB | Analog input channels. |
| D0A-D7A | Connected to FX2 PB0-PB7. |
| D0B-D7B | Connected to FX2 PD0-PD7. |
Firmware
Note: The firmware is flashed into the device permanently.
EEPROM layout
The device has a 8KB I²C EEPROM with the following layout:
c2 47 05 31 21 00 00 04 XX XX XX XX XX XX .. ..
Description:
| Bytes | Description |
|---|---|
| 0 | 0xc2: FX2 "c2 load" mode, i.e. VID/PID/DID are loaded from EEPROM as the firmware. |
| 1-2 | 0x0547: USB vendor ID (VID). |
| 3-4 | 0x2131: USB product ID (PID). |
| 5-6 | 0x0000: USB device ID (DID). |
| 7 | 0x04: FX2 configuration byte (see FX2 TRM for details). |
| 8-1917h | Firmware. |
| 1918h -1fffh | All-0xff. |
Photos
Device, top
Device, bottom
PCB, top
PCB, bottom
2x mux, ADC, shift-reg
(1 of 2) mux, ADC, shift-reg, USB, EEPROM, crystal
Jacks, reed switches, calibration. 2x mux, ADC, USB, crystal
