3.20.1 Source Side Junction Current

Bias-independent calculations:

The bias-independent source side junction current, $I_{sbs}$, is determined as shown below:

$I_{sbs} = ASEJ \cdot J_{ss}(T) + PSEJ \cdot J_{sws}(T) + TFIN \cdot NFIN_{total} \cdot J_{swgs}(T) \qquad (3.547)$

$NV_{tms} = \dfrac{kT}{q} \cdot NJS \qquad (3.548)$

$XExpBVS = exp \Bigg( - \dfrac{BVS}{NV_{tms}} \Bigg) \cdot XJBVS \qquad (3.549)$

$T_b = 1 + \dfrac{IJTHSFWD}{I_{sbs}} - XExpBVS \qquad (3.550)$

$V_{jsmFwd} = NV_{tms} \cdot ln \Bigg( \dfrac{T_b + \sqrt{ {T_b}^2 + 4 \cdot XExpBVS}}{2} \Bigg) \qquad (3.551)$

$T_0 = exp \Bigg( \dfrac{V_{jsmFwd}}{NV_{tms}} \Bigg) \qquad (3.552)$

$IV_{jsmFwd} = I_{sbs} \Bigg( T_0 - \dfrac{XExpBVS}{T_0} + XExpBVS - 1 \Bigg) \qquad (3.553)$

$S_{slpFwd} = \dfrac{I_{sbs}}{NV_{tms}} \cdot \Bigg( T_0 + \dfrac{XExpBVS}{T_0} \Bigg) \qquad (3.554)$

$V_{jsmRev} = -BVS - NV_{tms} \cdot ln \Bigg[ \dfrac{1}{XJBVS} \cdot \Bigg( \dfrac{IJTHSREV}{I_{sbs}} - 1 \Bigg) \Bigg] \qquad (3.555)$

$T_1 = XJBVS \cdot exp \Bigg( - \dfrac{BVS + V_{jsmRev}}{NV_{tms}} \Bigg) \qquad (3.556)$

$IV_{jsmRev} = I_{sbs} \cdot (1 + T_1) \qquad (3.557)$

$S_{slpRev} = -I_{sbs} \cdot \dfrac{T_1}{NV_{tms}} \qquad (3.558)$

Bias-dependent calculations:

The bias dependent source side junction current, $I_{es}$, is determined as shown below:

If $V_{es} < V_{jsmRev}$,

$I_{es} = \Bigg[ exp \Bigg( \dfrac{V_{es}}{NV_{tms}} \Bigg) - 1 \Bigg] \cdot \Big[ IV_{jsmRev} + S_{slpRev} \cdot (V_{es} - V_{jsmRev}) \Big] \qquad (3.560)$

Else if $V_{jsmRev} \le V_{es} \le V_{jsmFwd}$,

$I_{es} = I_{sbs} \cdot \Bigg[ exp \Bigg( \dfrac{V_{es}}{NV_{tms}} \Bigg) + XExpBVS - 1 - XJBVS \cdot exp \Bigg( - \dfrac{BVS + V_{es}}{NV_{tms}} \Bigg) \Bigg]$

$(3.561)$

Else $V_{es} > V_{jsmFwd}$,

$I_{es} = IV_{jsmFwd} + S_{slpFwd} \cdot (V_{es} - V_{jsmFwd}) \qquad (3.562)$

Including source side junction tunneling current:

$\begin{aligned} I_{es1} &= ASEJ \cdot J_{tss}(T) \times \\ & \Bigg[ exp \Bigg( \dfrac{-V_{es} / (k \cdot TNOM / q) / NJTS(T) \times VTSS}{max(VTSS - V_{es}, VTSS \cdot 10^{-3} )} \Bigg) - 1 \Bigg] \end{aligned} \qquad (3.563)$

$\begin{aligned} I_{es2} &= PSEJ \cdot J_{tssws}(T) \times \\ & \Bigg[ exp \Bigg( \dfrac{-V_{es} / (k \cdot TNOM / q) / NJTSSW(T) \times VTSSWS}{max(VTSSWS - V_{es}, VTSSWS \cdot 10^{-3} )} \Bigg) - 1 \Bigg] \end{aligned} \qquad (3.564)$

$\begin{aligned} I_{es3} &= TFIN \cdot NFIN_{total} \cdot J_{tsswgs}(T) \times \\ & \Bigg[ exp \Bigg( \dfrac{-V_{es} / (k \cdot TNOM / q) / NJTSSWG(T) \times VTSSWGS}{max(VTSSWGS - V_{es}, VTSSWGS \cdot 10^{-3} )} \Bigg) - 1 \Bigg] \end{aligned} \qquad (3.565)$

$I_{es} = I_{es} - (I_{es1} + I_{es2} + I_{es3}) \qquad (3.566)$