LTC6421-20 PIN FUNCTIONS+INA, –INA, –INB, +INB (Pins 1, 2, 5, 6): Differential –OUTA, +OUTA, –OUTB, +OUTB (Pins 16, 17, 11, 10): Inputs of A and B channel respectively. Differential Outputs of channels A and B respectively. V– (Pins 3, 4, 13, 14, 21): Negative Power Supply. All VOCMA, VOCMB (Pins 19, 8): These pins set the output four pins, as well as the exposed back, must be connected common mode voltage for the respective channel. They to same voltage/ground. are internally separate. A 0.1μF external bypass capacitor ENABLEA is recommended. , ENABLEB (Pins 9, 18): Logic inputs. If low, the amplifi er is enabled. If high, the amplifi er is disabled Exposed Pad (Pin 21): V –. The Exposed Pad must be and placed in a low-power shutdown mode, making connected to same voltage/ground as pins 3, 4, 13, 14. the amplifi er outputs high impedance. These pins are internally separate. These pins should not be left fl oating. V+ A , V+ B (Pins 15, 20, 7, 12 ): Positive Power Supply (Normally tied to 3V or 3.3V). Supply pins of A and B channels are internally separate. Bypass each pin with 1000pF and 0.1μF capacitors as close to the pins as possible. BLOCK DIAGRAM V+ A VOCMA ENABLEA +OUTA 20 19 18 17 RF R R G 1000Ω OUT 100Ω 12.5Ω +INA 1 – + 16 –OUTA RG ROUT 100Ω 12.5Ω 15 V+ A –INA 2 + – RF 1000Ω V– 3 14 V– V– 4 R 13 V– F RG R 1000Ω OUT 100Ω 12.5Ω –INB 5 + – 12 V+ B R R G OUT 100Ω 12.5Ω +INB 6 – + 11 –OUTB RF 1000Ω 7 8 9 10 642120 BD V+ B VOCMB ENABLEB +OUTB 642120fb 7 Document Outline FEATURES DESCRIPTION APPLICATIONS TYPICAL APPLICATION ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION ORDER INFORMATION SELECTOR GUIDE DC ELECTRICAL CHARACTERISTICS AC ELECTRICAL CHARACTERISTICS TYPICAL PERFORMANCE CHARACTERISTICS PIN FUNCTIONS BLOCK DIAGRAM APPLICATIONS INFORMATION TYPICAL APPLICATIONS PACKAGE DESCRIPTION REVISION HISTORY TYPICAL APPLICATION RELATED PARTS