ECL flip-flop help

[allanw]

I've been trying to figure out this ECL flip-flop which is a part of the HP 8116A function generator I've been trying to fix. It's an MC10231P: http://www.datasheetcatalog.org/datasheet/motorola/MC10231L.pdf

No matter what I do, I can't get valid outputs from the chip. I've even ordered a replacement for the chip and that one still doesn't work, so I think it's human error.

My connections are like this: voltage source positive end to ground, and negative end to -5.2V rail. I connect -5.2V to pin 8, Vee, and ground to Vcc1 and Vcc2. Hopefully this is correct. The new chip draws 54mA in this state, the old chip I pulled from the 8116A draws 33mA.

The datasheet says the flip flop has asynchronous set/reset, so I've tried setting R = L and S = H (R = -5.2V, S = 0V). Then I measured the outputs to be Q = +0.15V and ~Q = 0V. Then I flipped R = H and S = L, and the outputs were Q = 0V and ~Q = +0.07V. I've even tried clocking it with D = L and H, and R = L, S = L but nothing happens either. What am I doing wrong here? :/

[jahonen]

I think that ECL outputs need a termination voltage via resistor to work correctly. For details, see Termination of ECL Logic Devices.

Regards,
Janne

[Time]

Are you testing the chip by itself or are you testing the chip on the actual PCB of the function generator?

I've been trying to figure out this ECL flip-flop which is a part of the HP 8116A function generator I've been trying to fix. It's an MC10231P: http://www.datasheetcatalog.org/datasheet/motorola/MC10231L.pdf

No matter what I do, I can't get valid outputs from the chip. I've even ordered a replacement for the chip and that one still doesn't work, so I think it's human error.

My connections are like this: voltage source positive end to ground, and negative end to -5.2V rail. I connect -5.2V to pin 8, Vee, and ground to Vcc1 and Vcc2. Hopefully this is correct. The new chip draws 54mA in this state, the old chip I pulled from the 8116A draws 33mA.

The datasheet says the flip flop has asynchronous set/reset, so I've tried setting R = L and S = H (R = -5.2V, S = 0V). Then I measured the outputs to be Q = +0.15V and ~Q = 0V. Then I flipped R = H and S = L, and the outputs were Q = 0V and ~Q = +0.07V. I've even tried clocking it with D = L and H, and R = L, S = L but nothing happens either. What am I doing wrong here? :/

[allanw]

I think that ECL outputs need a termination voltage via resistor to work correctly. For details, see Termination of ECL Logic Devices.

Regards,
Janne

I think you're right. I'll try terminating the outputs with 100 ohm to -2V.

I'm testing the flip flop out of circuit.