Table of Contents
Description
This part was taken from a Motronic M1.7.3 engine control unit (ECU), which was commonly used on 1.6L & 1.8L 4-cylinder BMWs of the mid-E36 generation. While this chip was likely used on a number of ECUs, the specific one in this case had Bosch PN 0 261 203 661.
Functionally, this chip is a 6-element array of TVS diodes connected in parallel with various analog engine sensors' inputs. It provides bipolar protection to the MCU's ADC inputs.
Package
Label (top):
30132 (Bosch internal PN) [Bosch Logo] 136
Die
Decap Steps: (Bic lighter + water quench) x 2 cycles Selective crushing with pliers and bench vise Capture Details: Imaging device: Keyence VHX-2000 Magnification: 500X Markings: [Bosch Logo] J52B CJ52B (likely a reference to the commercial PN used by Bosch)
Imaged using normal / center lighting:
Imaged using edge lighting, for enhanced shadow contrast:
Note: The metal layer got a little smudged in some places during mechanical decapsulation. These are ~2X downsampled versions of the original images. Full resolution versions (6-9MB) can be provided. On the to-do list…
