SI1000-C-GM Silicon Laboratories Inc, SI1000-C-GM Datasheet - Page 199

• Manufacturer Part Number: SI1000-C-GM
• Description: IC TXRX MCU + EZRADIOPRO
• Manufacturer: Silicon Laboratories Inc

Specifications of SI1000-C-GM

• Package / Case: 42-QFN
• Frequency: 240MHz ~ 960MHz
• Data Rate - Maximum: 256kbps
• Modulation Or Protocol: FSK, GFSK, OOK
• Applications: General Purpose
• Power - Output: 20dBm
• Sensitivity: -121dBm
• Voltage - Supply: 1.8 V ~ 3.6 V
• Current - Receiving: 18.5mA
• Current - Transmitting: 85mA
• Data Interface: PCB, Surface Mount
• Memory Size: 64kB Flash, 4kB RAM
• Antenna Connector: PCB, Surface Mount
• Number Of Receivers: 1
• Number Of Transmitters: 1
• Wireless Frequency: 240 MHz to 960 MHz
• Interface Type: UART, SMBus, SPI, PCA
• Output Power: 20 dBm
• Operating Supply Voltage: 0.9 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Maximum Supply Current: 4.1 mA
• Minimum Operating Temperature: - 40 C
• Modulation: FSK, GFSK, OOK
• Protocol Supported: C2, SMBus
• Core: 8051
• Program Memory Type: Flash
• Program Memory Size: 64 KB
• Data Ram Size: 4352 B
• Supply Current (max): 4.1 mA
• Cpu Family: Si100x
• Device Core: 8051
• Device Core Size: 8b
• Frequency (max): 25MHz
• Total Internal Ram Size: 4.25KB
• # I/os (max): 22
• Number Of Timers - General Purpose: 4
• Operating Supply Voltage (typ): 2.5/3.3V
• Operating Supply Voltage (max): 3.6V
• Operating Supply Voltage (min): 1.8V
• On-chip Adc: 18-chx10-bit
• Instruction Set Architecture: CISC
• Mounting: Surface Mount
• Pin Count: 42
• Package Type: QFN EP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Operating Temperature: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 336-1881-5

20.2.4. Automatic Gain Control (Crystal Mode Only) and SmaRTClock Bias Doubling
Automatic Gain Control allows the SmaRTClock oscillator to trim the oscillation amplitude of a crystal in
order to achieve the lowest possible power consumption. Automatic Gain Control automatically detects
when the oscillation amplitude has reached a point where it safe to reduce the drive current, therefore, it
may be enabled during crystal startup. It is recommended to enable Automatic Gain Control in most sys-
tems which use the SmaRTClock oscillator in Crystal Mode. The following are recommended crystal spec-
ifications and operating conditions when Automatic Gain Control is enabled:
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When using Automatic Gain Control, it is recommended to perform an oscillation robustness test to ensure
that the chosen crystal will oscillate under the worst case condition to which the system will be exposed.
The worst case condition that should result in the least robust oscillation is at the following system condi-
tions: lowest temperature, highest supply voltage, highest ESR, highest load capacitance, and lowest bias
current (AGC enabled, Bias Double Disabled).
To perform the oscillation robustness test, the SmaRTClock oscillator should be enabled and selected as
the system clock source. Next, the SYSCLK signal should be routed to a port pin configured as a push-pull
digital output. The positive duty cycle of the output clock can be used as an indicator of oscillation robust-
ness. As shown in Figure 20.2, duty cycles less than 55% indicate a robust oscillation. As the duty cycle
approaches 60%, oscillation becomes less reliable and the risk of clock failure increases. Increasing the
bias current (by disabling AGC) will always improve oscillation robustness and will reduce the output
clock’s duty cycle. This test should be performed at the worst case system conditions, as results at very
low temperatures or high supply voltage will vary from results taken at room temperature or low supply
voltage.
As an alternative to performing the oscillation robustness test, Automatic Gain Control may be disabled at
the cost of increased power consumption (approximately 200 nA). Disabling Automatic Gain Control will
provide the crystal oscillator with higher immunity against external factors which may lead to clock failure.
Automatic Gain Control must be disabled if using the SmaRTClock oscillator in self-oscillate mode.
Table 20.3 shows a summary of the oscillator bias settings. The SmaRTClock Bias Doubling feature allows
the self-oscillation frequency to be increased (almost doubled) and allows a higher crystal drive strength in
crystal mode. High crystal drive strength is recommended when the crystal is exposed to poor environmen-
tal conditions such as excessive moisture. SmaRTClock Bias Doubling is enabled by setting BIASX2
(RTC0XCN.5) to 1.
ESR < 50 k
Load Capacitance < 10 pF
Supply Voltage < 3.0 V
Temperature > –20 °C
Figure 20.2. Interpreting Oscillation Robustness (Duty Cycle) Test Results
25%
Safe Operating Zone
55%
Low Risk of Clock
Rev. 1.0
Failure
60%
High Risk of Clock
Failure
Si1000/1/2/3/4/5
Duty Cycle
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