LT1575/LT1577 ELECTRICAL CHARACTERISTICSTA = 25 ° C, VIN = 12V, GATE = 6V, IPOS = INEG = 5V, SHDN = 0.75V unless otherwise noted.SYMBOLPARAMETERCONDITIONSMINTYPMAXUNITS IQ Supply Current ● 5 12 19 mA VFB LT1575 Reference Voltage – 0.6 1.210 0.6 % ● – 1.0 1.210 1.0 % VOUT LT1575-1.5 Output Voltage – 0.6 1.500 0.6 % ● – 1.0 1.500 1.0 % LT1575-2.8 Output Voltage – 0.6 2.800 0.6 % ● – 1.0 2.800 1.0 % LT1575-3.3 Output Voltage – 0.6 3.300 0.6 % ● – 1.0 3.300 1.0 % LT1575-3.5 Output Voltage – 0.6 3.500 0.6 % ● – 1.0 3.500 1.0 % LT1575-5 Output Voltage – 0.6 5.000 0.6 % ● – 1.0 5.000 1.0 % Line Regulation 10V ≤ VIN ≤ 20V ● 0.01 0.03 %/V IFB FB Input Bias Current FB = VFB ● – 0.6 – 4.0 µA IOUT OUT Divider Current OUT = VOUT ● 0.5 1.0 1.5 mA AVOL LT1575 Large-Signal Voltage Gain VGATE = 3V to 10V ● 69 84 dB LT1575-1.5 Large-Signal Voltage Gain VGATE = 3V to 10V ● 67 82 dB LT1575-2.8 Large-Signal Voltage Gain VGATE = 3V to 10V ● 60 76 dB LT1575-3.3 Large-Signal Voltage Gain VGATE = 3V to 10V ● 60 75 dB LT1575-3.5 Large-Signal Voltage Gain VGATE = 3V to 10V ● 60 74 dB LT1575-5 Large-Signal Voltage Gain VGATE = 3V to 10V ● 56 71 dB VOL GATE Output Swing Low (Note 3) IGATE = 0mA ● 2.5 3.0 V VOH GATE Output Swing High IGATE = 0mA ● VIN – 1.6 VIN – 1 V IPOS + INEG Supply Current 3V ≤ IPOS ≤ 20V ● 0.3 0.625 1.0 mA Current Limit Threshold Voltage 42 50 58 mV ● 37 50 63 mV Current Limit Threshold Voltage 3V ≤ IPOS ≤ 20V ● – 0.20 – 0.50 %/V Line Regulation SHDN Sink Current Current Flows Into Pin ● 2.5 5.0 8.0 µA SHDN Source Current Current Flows Out of Pin ● – 8 – 15 – 23 µA SHDN Low Clamp Voltage ● 0.1 0.25 V SHDN High Clamp Voltage ● 1.50 1.85 2.20 V SHDN Threshold Voltage ● 1.18 1.21 1.240 V SHDN Threshold Hysteresis ● 50 100 150 mV The ● denotes specifications which apply over the full operating Because the LT1577 consists of two regulators in the package, the total temperature range. LT1577 power dissipation must be used for its junction temperature Note 1: Absolute Maximum Ratings are those values beyond which the life calculation. The total LT1577 PD = PD (Regulator 1) + PD (Regulator 2). of the device may be impaired. Note 3: The VGS(th) of the external MOSFET must be greater than Note 2: T 3V – V J is calculated from the ambient temperature TA and power OUT. dissipation PD according to the following formulas: LT1575CN8: TJ = TA + (PD • 100°CW) LT1575CS8: TJ = TA + (PD • 130°CW) LT1577CS: TJ = TA + (PD • 100°CW) 3