Low-Noise, 14V Input, 1A, PWMStep-Down ConvertersMAX1684/MAX1685Typical Operating Characteristics (Circuit of Figure 1, TA = +25°C, unless otherwise noted.) MAX1684MAX1684MAX1684EFFICIENCY vs. LOAD CURRENTEFFICIENCY vs. LOAD CURRENTEFFICIENCY vs. LOAD CURRENT(VIN = 3.3V, VOUT = 1.8V, 2.5V)(VOUT = 3.3V)(VOUT = 3.3V, PWM MODE) 100 100 100 A C 90 90 90 80 80 80 MAX1684/85 toc01 MAX1684/85 toc02 B MAX1684/85 toc03 D C A 70 A 70 70 D D 60 60 60 B 50 C E 50 50 40 B 40 EFFICIENCY (%) A: V 40 OUT = 2.5V LP MODE EFFICIENCY (%) EFFICIENCY (%) 30 F B: VOUT = 1.8V LP MODE 30 30 C: V A: V A: V OUT = 2.5V NORM MODE IN = 4V LP MODE IN = 4V 20 D: V 20 B: V 20 B: V OUT = 1.8V NORM MODE IN = 12V LP MODE IN = 5V C: V 10 E: V C: V OUT = 2.5V PWM MODE 10 IN = 4V NORMAL MODE 10 IN = 9V F: V D: V D: V OUT = 1.8V PWM MODE IN = 12V NORMAL MODE IN = 12V 0 0 0 0.1 1 10 100 1000 10,000 0.1 1 10 100 1000 10,000 1 10 100 1000 10,000 LOAD CURRENT (mA) LOAD CURRENT (mA) LOAD CURRENT (mA) MAX1684MAX1684MAX1685EFFICIENCY vs. LOAD CURRENTEFFICIENCY vs. LOAD CURRENTEFFICIENCY vs. LOAD CURRENT(VOUT = 5V)(VOUT = 5V, PWM MODE)(VOUT = 3.3V, PWM MODE) 100 100 100 D 90 90 B 90 A E V 80 IN = 4V E 80 MAX1684/85 toc04 80 MAX1684/85 toc06 C MAX1684/85 toc05 A 70 70 F 70 60 60 VIN = 5V 60 50 50 B 40 EFFICIENCY (%) 50 A: V 40 C IN = 6V LP MODE EFFICIENCY (%) EFFICIENCY (%) VIN = 9V B: VIN = 9V LP MODE 30 30 40 C: VIN = 12V LP MODE 20 D: V 20 A: V IN = 6V NORMAL MODE IN = 6V VIN = 12V 30 E: V B: V IN = 9V NORMAL MODE IN = 9V 10 10 F: V C: V IN = 12V NORMAL MODE IN =12V 20 0 0 0.1 1 10 100 1000 10,000 1 10 100 1000 10,000 1 10 100 1000 10,000 LOAD CURRENT (mA) LOAD CURRENT (mA) LOAD CURRENT (mA) MAX1685MAX1685MAX1685EFFICIENCY vs. LOAD CURRENTEFFICIENCY vs. LOAD CURRENTEFFICIENCY vs. LOAD CURRENT(V(V(VOUT = 3.3V)OUT = 5V PWM MODE)OUT = 5V) 100 100 100 C A B 90 A 90 90 80 80 80 E D MAX1684/85 toc07 MAX1684/85 toc08 MAX1684/85 toc09 C F D VIN = 6V 70 B 70 V 70 IN = 9V 60 60 60 50 50 50 40 40 40 EFFICIENCY (%) EFFICIENCY (%) EFFICIENCY (%) A: VIN = 6V LP MODE 30 30 30 B: VIN = 9V LP MODE A: V C: V IN = 4V LP MODE IN = 12V LP MODE 20 20 VIN =12V 20 B: V D: V IN = 12V LP MODE IN = 6V NORMAL MODE 10 C: V E: V IN = 4V NORMAL MODE 10 10 IN = 9V NORMAL MODE D: V F: V IN = 12V NORMAL MODE IN =12V NORMAL MODE 0 0 0 0.1 1 10 100 1000 10,000 1 10 100 1000 10,000 0.1 1 10 100 1000 10,000 LOAD CURRENT (mA) LOAD CURRENT (mA) LOAD CURRENT (mA) _______________________________________________________________________________________5