Datasheet
LPC2101_02_03_4 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 04 — 2 June 2009 9 of 37
NXP Semiconductors
LPC2101/02/03
Single-chip 16-bit/32-bit microcontrollers
[1] 5 V tolerant (if V
DD(3V3)
and V
DDA
≥ 3.0 V) pad providing digital I/O functions with TTL levels and hysteresis and 10 ns slew rate control.
[2] Open-drain 5 V tolerant (if V
DD(3V3)
and V
DDA
≥ 3.0 V) digital I/O I
2
C-bus 400 kHz specification compatible pad. It requires external
pull-up to provide an output functionality. Open-drain configuration applies to ALL functions on that pin.
[3] 5 V tolerant (if V
DD(3V3)
and V
DDA
≥ 3.0 V) pad providing digital I/O (with TTL levels and hysteresis and 10 ns slew rate control) and
analog input function. If configured for an input function, this pad utilizes built-in glitch filter that blocks pulses shorter than 3 ns. When
configured as an ADC input, digital section of the pad is disabled.
[4] 5 V tolerant (if V
DD(3V3)
and V
DDA
≥ 3.0 V) pad providing digital I/O functions with TTL levels and hysteresis and 10 ns slew rate control.
If configured for an input function, this pad utilizes built-in glitch filter that blocks pulses shorter than 3 ns.
[5] A LOW level during reset on pin P0.14 is considered as an external hardware request to start the ISP command handler.
[6] Open-drain 5 V tolerant (if V
DD(3V3)
and V
DDA
≥ 3.0 V) digital I/O I
2
C-bus 400 kHz specification compatible pad. It requires external
pull-up to provide an output functionality. Open-drain configuration applies only to I
2
C function on that pin.
[7] Pad provides special analog functionality.
[8] For lowest power consumption, pin should be left floating when the RTC is not used.
[9] See
LPC2101/02/03 User manual UM10161
for details.
V
SS
7, 19, 43 I Ground: 0 V reference.
V
SSA
31 I Analog ground: 0 V reference. This should be nominally the same voltage as
V
SS
but should be isolated to minimize noise and error.
V
DDA
42 I Analog 3.3 V power supply: This should be nominally the same voltage as
V
DD(3V3)
but should be isolated to minimize noise and error. The level on this
pin also provides a voltage reference level for the ADC.
V
DD(1V8)
5I1.8 V core power supply: This is the power supply voltage for internal
circuitry and the on-chip PLL.
V
DD(3V3)
17, 40 I 3.3 V pad power supply: This is the power supply voltage for the I/O ports.
VBAT 4 I RTC power supply: 3.3 V on this pin supplies the power to the RTC.
Table 3. Pin description
…continued
Symbol Pin Type Description