MAX1730EUB-T Maxim Integrated Products, MAX1730EUB-T Datasheet - Page 7

• Manufacturer Part Number: MAX1730EUB-T
• Description: Charge Pumps 50mA Regulated Step-Down
• Manufacturer: Maxim Integrated Products

Specifications of MAX1730EUB-T

• Function: Step Down
• Output Voltage: 1.8 V, 1.9 V
• Output Current: 50 mA
• Maximum Operating Temperature: + 85 C
• Package / Case: uMAX-10
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT

Figure 1. 1:1 Capacitor Configuration
Figure 2. 3:2 Capacitor Configuration
To maximize efficiency, the MAX1730 automatically
switches between charge-pump configurations (Figures
1, 2, and 3). Efficiency is greatest when the IN/OUT volt-
age ratio is close to the voltage ratio of the selected
capacitor configuration and decreases for output volt-
ages lower than the divider ratio. To choose between
configurations, the MAX1730 senses the input voltage
and the output voltage. The MAX1730 uses a control
scheme with hysteresis to prevent oscillation between
capacitor configurations.
V
NOTE: SWITCH STATES SET FOR STAGE 1.
V IN
OUT
=
NOTE: SWITCH STATES SET FOR STAGE 1.
ALL SWITCHES REVERSE STATE FOR STAGE 2.
2
3
V
IN
V
IN
ALL SWITCHES REVERSE STATE FOR STAGE 2.
50mA Regulated Step-Down Charge Pump
C
IN
C
_______________________________________________________________________________________
IN
C1
C
OUT
C1
C2
For an output voltage of 1.8V, connect FB to GND. For
an output voltage of 1.9V, connect FB to IN.
Figure 3. 2:1 Capacitor Configuration
NOTE: SWITCH STATES SET FOR STAGE 1.
for 1.8V or 1.9V Logic
V IN
ALL SWITCHES REVERSE STATE FOR STAGE 2.
C
IN
C2
Applications Information
C1
Setting the Output Voltage
C
OUT
V
OUT
=
1
2
V
C
IN
OUT
V
C2
OUT
= V
IN
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