Single/Dual/Quad, Low-Cost, SOT23, Micropower, Rail-to-Rail I/O Op Amps______________________________________________________________Pin DescriptionPINMAX4040MAX4043NAMEFUNCTIONMAX4041MAX4042MAX4044SOT23-5SO/µMAXµMAXSO Amplifier Output. High impedance 1 6 6 — — — — OUT when in shutdown mode. Negative Supply. Tie to ground for 2 4 4 4 4 4 11 VEE single-supply operation. 3 3 3 — — — — IN+ Noninverting Input 4 2 2 — — — — IN- Inverting Input 5 7 7 8 10 14 4 VCC Positive Supply 5, 7, No Connection. Not internally con- — 1, 5, 8 1, 5 — — — N.C. 8, 10 nected. Shutdown Input. Drive high, or tie to — — 8 — — — — SHDN VCC for normal operation. Drive to VEE to place device in shutdown mode. MAX4040–MAX4044 OUTA, Outputs for Amplifiers A and B. High — — — 1, 7 1, 9 1, 13 1, 7 OUTB impedance when in shutdown mode. INA-, — — — 2, 6 2, 8 2, 12 2, 6 Inverting Inputs to Amplifiers A and B INB- INA+, Noninverting Inputs to Amplifiers A — — — 3, 5 3, 7 3, 11 3, 5 INB+ and B Shutdown Inputs for Amplifiers A SHDNA, and B. Drive high, or tie to V — — — — 5, 6 6, 9 — CC for SHDNB normal operation. Drive to VEE to place device in shutdown mode. OUTC, — — — — — — 8, 14 Outputs for Amplifiers C and D OUTD INC-, — — — — — — 9, 13 Inverting Inputs to Amplifiers C and D IND- INC+, Noninverting Inputs to Amplifiers C — — — — — — 10, 12 IND+ and D _______________Detailed Description an excellent choice for precision or general-purpose, low-voltage battery-powered systems. Rail-to-Rail Input Stage Since the input stage consists of NPN and PNP pairs, The MAX4040–MAX4044 have rail-to-rail inputs and the input bias current changes polarity as the common- rail-to-rail output stages that are specifically designed mode voltage passes through the crossover region. for low-voltage, single-supply operation. The input Match the effective impedance seen by each input to stage consists of separate NPN and PNP differential reduce the offset error caused by input bias currents stages, which operate together to provide a common- flowing through external source impedances (Figures mode range extending to both supply rails. The 1a and 1b). The combination of high source impedance crossover region of these two pairs occurs halfway plus input capacitance (amplifier input capacitance between VCC and VEE. The input offset voltage is typi- plus stray capacitance) creates a parasitic pole that cally 200µV. Low operating supply voltage, low supply produces an underdamped signal response. Reducing current, rail-to-rail common-mode input range, and rail- input capacitance or placing a small capacitor across to-rail outputs make this family of operational amplifiers the feedback resistor improves response in this case. 8_______________________________________________________________________________________