IC-HTP Datasheet, PDF (13/51 Pages) IC-Haus GmbH – DUAL CW P-TYPE LASER DIODE DRIVER

iC-HTP
DUAL CW P-TYPE
LASER
DIODE
DRIVER
preliminary
Rev B1, Page 13/51
MICROCONTROLLER MODE
Setting pin EMC to hi configures iC-HTP for microcon-
troller mode (MCU mode). EMC pin must be set us-
ing a pull-up resistor or directly short-circuited to VDD
pin. Several parameters can be configured through a
microcontroller via I²C or SPI communication. More
information about the serial communication interface
can be found on page 26.
The configuration of the internal parameters of iC-HTP
must be done in configuration mode. In this mode, the
configuration memory can be written and read back
without changing the previous configuration state of
iC-HTP. Once the configuration is considered as valid,
iC-HTP can be switched to operation mode. These two
modes are configured by the MODE register. The time
elapsed in configuration may not exceed 40 ms. If this
timeout is exceeded, both channels will be switched off.
More information on page 38.
Each individual channel can be enabled by setting pin
ECx to hi. Setting register bits DISCx to 1 disables the
corresponding channel. If either pin ECx is lo or register
bits DISCx is 1, the corresponding channel is disabled.
DISC1
0
1
Addr. 0x10; bit 3
Channel 1 can be enabled by pin EC1
Channel 1 cannot be enabled by pin EC1
R/W 1
Table 6: Disable channel 1
ADCC1(2:0)
Addr. 0x10; bit 7:5
R/W 000
0xx
Channel 1 ADC disabled
100
Channel 1 ADC sourced by V(MDK1), ADFNS1 = 1,
CMES1 = 0
100
Channel 1 ADC sourced by V(PLR1), ADFNS1 = 0,
CMES1 = 0
100
Channel 1 ADC sourced by ACC current sensor,
CMES1 = 1
101
Channel 1 ADC sourced by V(VB)
110
Channel 1 ADC sourced by V(VBL1)
111
Channel 1 ADC sourced by V(LDA1)
Table 8: ADC channel 1 source selection
ADCC2(2:0)
Addr. 0x15; bit 7:5
R/W 000
0xx
Channel 2 ADC disabled
100
Channel 2 ADC sourced by V(MDK2), ADFNS2 = 1,
CMES2 = 0
100
Channel 2 ADC sourced by V(PLR2), ADFNS2 = 0,
CMES2 = 0
100
Channel 2 ADC sourced by ACC current sensor,
CMES2 = 1
101
Channel 2 ADC sourced by V(VDD)
110
Channel 2 ADC sourced by V(VBL2)
111
Channel 2 ADC sourced by V(LDA2)
Table 9: ADC channel 2 source selection
DISC2
0
1
Addr. 0x15; bit 3
Channel 2 can be enabled by pin EC2
Channel 2 cannot be enabled by pin EC2
R/W 1
Table 7: Disable channel 2
Different voltages can be measured using a 10 bit A/D
converter with two resolutions. The following internal
voltages can be measured:
• V(LDAx) up to 11 V with 11.81 mV resolution
• V(VDD) up to 8 V with 8.6 mV resolution
• V(VB) up to 11 V with 11.81 mV resolution
• V(VBLx) up to 11 V with 11.81 mV resolution
• V(MDKx) up to 1.1 V with 1.075 mV resolution
• V(PLRx) up to 1.1 V with 1.075 mV resolution
• V(RACC) up to 1.1 V with 1.075 mV resolution
The register bits ADCCx select the signal measured
with the 10 bit A/D converter.
With ADCCx(2:0) = 100, the signal to the A/D converter
is selected by register bit ADFNSx. With ADFNSx = 0
the measuring point to the A/D converter is the internal
sense node of the internal programmable logarithmic
monitor resistor (PLR). With ADFNSx = 1 the sensing
point is connected directly to MDKx pin. Note that in this
case, only voltages from 0 to 1.1 V can be monitored for
the A/D converter. With the CMESx bit, the ADC can be
used for laser current measurement in ACC mode. For
this measurement, ADCCx register must be set to 100.
As shown in figure 7, a fraction of the current delivered
by the driver to the laser is mirrored to a resistor. The
voltage drop at this resistor is sourced to the ADC. For a
more detailed explanation of the current measurement,
please refer to the ADC chapter.
ADFNS1
0
1
Addr. 0x1A; bit 2
R/W 0
ADC measurement PLR1 after level shifting (sense)
ADC measurement MDK1 pad (force)
Table 10: ADC channel 1 force/sense selection