C8051F962-A-GM Silicon Labs, C8051F962-A-GM Datasheet - Page 269

• Manufacturer Part Number: C8051F962-A-GM
• Description: 8-bit Microcontrollers - MCU 128KB, DC-DC, AES DQFN76
• Manufacturer: Silicon Labs

Specifications of C8051F962-A-GM

• Rohs: yes
• Core: 8051
• Processor Series: C8051
• Data Bus Width: 8 bit
• Maximum Clock Frequency: 25 MHz
• Program Memory Size: 128 KB
• Data Ram Size: 8448 B
• On-chip Adc: Yes
• Operating Supply Voltage: 2.5 V to 3.3 V
• Operating Temperature Range: - 40 C to + 85 C
• Package / Case: DQFN-76
• Mounting Style: SMD/SMT
• Number Of Programmable I/os: 57
• Number Of Timers: 4

20. On-Chip DC-DC Buck Converter (DC0)
C8051F96x devices include an on-chip step down dc-dc converter to efficiently utilize the energy stored in
the battery, thus extending the operational life time. The dc-dc converter is a switching buck converter with
an input supply of 1.8 to 3.8 V and an output that is programmable from 1.8 to 3.5 V in steps of 0.1 V. The
battery voltage should be at least 0.4 V higher than the programmed output voltage. The programmed out-
put voltage has a default value of 1.9 V. The dc-dc converter can supply up to 250 mW. The dc-dc con-
verter can be used to power the MCU and/or external devices in the system (e.g., an RF transceiver).
The dc-dc converter has a built in voltage reference and oscillator, and will automatically limit or turn off the
switching activity in case the peak inductor current rises beyond a safe limit or the output voltage rises
above the programmed target value. This allows the dc-dc converter output to be safely overdriven by a
secondary power source (when available) in order to preserve battery life. When enabled, the dc-dc con-
verter can source current into the output capacitor, but cannot sink current. The dc-dc converter’s settings
can be modified using SFR registers described in Section 20.8.
Figure 20.1 shows a block diagram of the buck converter.
4.7 uF
+ 0.01uF
+ 0.1uF
Figure 20.1. Step Down DC-DC Buck Converter Block Diagram
VBATDC
VBAT
MBYP
Control
SFR
Control Logic
M1
Reference
Oscillator
Voltage
Rev. 0.5
Local
GNDDC
DC/DC Converter
GND
IND
VDC
C8051F96x
0.56 uH
+0.1uF
2.2 uF
+0.01uF
I
load
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