Booster transistor Q1 can handle current and voltage beyond 431 max IC and dissipation limits, while the 3.5-V voltage divider programs a constant I_S

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Other Materials from the Main Document

• Article «Precision programmable current sink»
• Figure 1. The floated anode serves as a sense pin for active current sink regulation
• Figure 2. Booster transistor Q1 can handle current and voltage beyond 431 max IC and dissipation limits, while the 3.5-V voltage divider programs a constant I_S
• Figure 3. DAC control of I_S, the DAC signal is inverted, while Z2 provides the necessary level shift
• Figure 4. PWM control of I_S, where I_S is the ratio of the PWM duty factor and R1
• Figure 5. The addition of R5 and C2 provides faster settling times with a 2nd-order ripple filter
• Figure 6. The combined current sink and small system power supply where the max I_S is 1 A, Max V_S is 20 V, and I_S = D