CY8C58LP Datasheet, PDF (54/122 Pages) Cypress Semiconductor – Programmable System-on-Chip (PSoC®)

PSoC^® 5LP: CY8C58LP Family
PRELIMINARY
Datasheet
Table 8-3. Bandwidth
Gain
1
24
48
50
Bandwidth
6.0 MHz
340 kHz
220 kHz
215 kHz
Figure 8-9. PGA Resistor Settings
V_in
0
R1
R2
V_ref
1
20 k or 40 k
20 k to 980 k
S
V_ref
0
V_in
1
The PGA is used in applications where the input signal may not
be large enough to achieve the desired resolution in the ADC, or
dynamic range of another SC/CT block such as a mixer. The gain
is adjustable at runtime, including changing the gain of the PGA
prior to each ADC sample.
8.6.4 TIA
The Transimpedance Amplifier (TIA) converts an internal or
external current to an output voltage. The TIA uses an internal
feedback resistor in a continuous time configuration to convert
input current to output voltage.For an input current I_in, the output
voltage is V_REF - I_in x R_fb, where V_REF is the value placed on the
non inverting input. The feedback resistor Rfb is programmable
between 20 KΩ and 1 MΩ through a configuration register.
Table 8-4 shows the possible values of Rfb and associated
configuration settings.
Table 8-4. Feedback Resistor Settings
Configuration Word
000b
001b
010b
011b
100b
101b
110b
111b
Nominal R_fb (KΩ)
20
30
40
60
120
250
500
1000
The TIA configuration is used for applications where an external
sensor's output is current as a function of some type of stimulus
such as temperature, light, magnetic flux etc. In a common
application, the voltage DAC output can be connected to the
V_REF TIA input to allow calibration of the external sensor bias
current by adjusting the voltage DAC output voltage.
8.7 LCD Direct Drive
The PSoC Liquid Crystal Display (LCD) driver system is a highly
configurable peripheral designed to allow PSoC to directly drive
a broad range of LCD glass. All voltages are generated on chip,
eliminating the need for external components. With a high
multiplex ratio of up to 1/16, the CY8C58LP family LCD driver
system can drive a maximum of 736 segments. The PSoC LCD
driver module was also designed with the conservative power
budget of portable devices in mind, enabling different LCD drive
modes and power down modes to conserve power.
PSoC Creator provides an LCD segment drive component. The
component wizard provides easy and flexible configuration of
LCD resources. You can specify pins for segments and
commons along with other options. The software configures the
device to meet the required specifications. This is possible
because of the programmability inherent to PSoC devices.
Key features of the PSoC LCD segment system are:
■ LCD panel direct driving
■ Type A (standard) and Type B (low power) waveform support
■ Wide operating voltage range support (2 V to 5 V) for LCD
panels
■ Static, 1/2, 1/3, 1/4, 1/5 bias voltage levels
■ Internal bias voltage generation through internal resistor ladder
■ Up to 62 total common and segment outputs
■ Up to 1/16 multiplex for a maximum of 16 backplane/common
outputs
■ Up to 62 front plane/segment outputs for direct drive
■ Drives up to 736 total segments (16 backplane x 46 front plane)
■ Up to 64 levels of software controlled contrast
■ Ability to move display data from memory buffer to LCD driver
through DMA (without CPU intervention)
■ Adjustable LCD refresh rate from 10 Hz to 150 Hz
■ Ability to invert LCD display for negative image
■ Three LCD driver drive modes, allowing power optimization
Figure 8-11. LCD System
Global
Clock
LCD
DAC
Figure 8-10. Continuous Time TIA Schematic
R fb
I _in
Vout
V ref
UDB
PIN
LCD Driver
Block
DMA
Display
RAM
PHUB
Document Number: 001-84932 Rev. **
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