# Datasheet-a-Day W31 2020

Slightly fewer datasheets this week, because I’m reading “Op Amps For Everyone”, which is a 464-page thing about op amps from TI. That’s a bit too long to manage one of them in a day!

## 2020-07-27: Various BJT datasheets

In the same spirit as looking at jellybean diode datasheets last week, I looked at:

Important characteristics:

• Max voltage (CE, CB, BE), current (C), power

• Thermal

• Current gain (DC and small signal)

• CE saturation voltage

• Input/output capacitance

• Gain/bandwidth product

• Switching times

• Temperature dependence of parameters

• Parameter interdependence (e.g. beta as a function of I_C, V_CE(sat) as a function of I_C)

## 2020-07-28: Data Converter Codes—Can You Decode Them? (Analog MT-009)

Very simple description of correspondence between analogue values and digital codes for ADCs and DACs. Simplest case is normal binary codes. Another option is Gray codes, often used internally by ADCs, converted to normal binary for output. For signed values, code options are offset binary, two’s complement, plus some less common ones.

## 2020-07-28: The Importance of Data Converter Static Specifications—Don’t Lose Sight of the Basics! (Analog MT-010)

Another basic one: it’s like they reset the difficulty level of this MT-xxx series!

Quantization in ADCs and DACs.- Ideal transfer characteristic: D = K + G A, where D = digital code, A = analog signal, K and G constants.

Offset error: for a unipolar converter, K = 0 ideally; for a bipolar converter, K = -1 MSB ideally; offset error is the difference between the converter’s real K and these ideal values.

Gain error: difference between converter’s actual gain and ideal G, expressed either as a percentage difference or the contribution of gain error to the total error at full-scale.

Integral nonlinearity error: maximum deviation of true transfer characteristic from ideal straight line.

Differential nonlinearity error: largest deviation from ideal difference in A for a 1 LSB difference in D; results in non-monotonicity (if |DNL| >= 1 LSB), wide codes and missing codes.

## 2020-07-29: Various FET datasheets

I looked at:

Important characteristics:

• Absolute maximum voltages and currents

• Forward transconductance

• Capacitance values

• On resistance

• Turn-on/off times

Much more that I don’t understand yet. Only on Chapter 2 of TAoE...