MAX3301EETJ Maxim Integrated, MAX3301EETJ Datasheet - Page 13

• Manufacturer Part Number: MAX3301EETJ
• Description: USB Interface IC
• Manufacturer: Maxim Integrated

Specifications of MAX3301EETJ

• Operating Supply Voltage: 3 V to 4.5 V
• Operating Supply Current: 5 uA

The USB OTG specification defines a dual-role USB
device that acts either as an A device or as a B device.
The A device supplies power on V
serves as the USB host. The B device serves as the ini-
tial peripheral and requires circuitry to monitor and pulse
V
The MAX3301E/MAX3302E combine a low- and full-
speed USB transceiver with additional circuitry required
by a dual-role device. The MAX3301E/MAX3302E
employ flexible switching circuitry to enable the device
to act as a dedicated host or peripheral USB transceiv-
er. For example, the charge pump can be turned off and
the internal regulator can be powered from V
bus-powered peripheral applications.
The Selector Guide shows the differences between the
MAX3301E and MAX3302E. The MAX3301E powers up
in its lowest power state and must be turned on by set-
ting the sdwn bit to 0. The MAX3302E powers up in the
operational, VP/VM USB mode. This allows a micro-
processor (µP) to use the USB port for power-on boot-
up, without having to access I
into low-power shutdown, set the sdwn bit to 0. In the
MAX3302E, special-function register 2 can be
addressed at I
locations 16h, 17h) to support USB OTG serial-interface
engine (SIE) implementations that are limited to I
register addresses between 0h and 15h.
The MAX3301E/MAX3302E transceiver complies with
the USB version 2.0 specification, and operates at full-
speed (12Mbps) and low-speed (1.5Mbps) data rates.
Set the data rate with the SPD input. Set the direction of
data transfer with the OE/INT input. Alternatively, control
transceiver operation with control register 1 (Table 7)
and special-function registers 1 and 2 (see Tables 14,
15, and 16).
Internal level shifters allow the system-side interface to
run at logic-supply voltages as low as +1.65V. Interface
logic signals are referenced to the voltage applied to
the logic-supply voltage, V
The MAX3301E/MAX3302E’s OTG-compliant charge
pump operates with +3V to +4.5V input supply voltages
(V
output on V
put current that an A device is required to supply.
Connect a 0.1µF flying capacitor between C+ and C-.
Bypass V
USB On-the-Go Transceivers and Charge Pumps
BUS
CC
) and supplies a +4.8V to +5.25V OTG-compatible
. These initial roles can be reversed using HNP.
BUS
BUS
to GND with a 1µF to 6.5µF capacitor, in
2
C register location 10h, 11h (as well as
while sourcing the 8mA or greater out-
______________________________________________________________________________________
Detailed Description
L
.
2
C. To put the MAX3302E
Level Shifters
BUS
Charge Pump
Transceiver
and initially
BUS
2
for
C
Figure 12. Comparator Network Diagram
accordance with USB OTG specifications. The charge
pump can be turned off to conserve power when not
used. Control of the charge pump is set through the
vbus_drv bit (bit 5) of control register 2 (see Table 8).
An internal 3.3V linear regulator powers the transceiver
and the internal 1.5kΩ D+/D- pullup resistor. Under the
control of internal register bits, the linear regulator can be
powered from V
settings are controlled by the reg_sel bit (bit 3) in special-
function register 2 (Tables 15 and 16). This flexibility
allows the system designer to configure the MAX3301E/
MAX3302E for virtually any USB power situation.
The output of the TRM is not a power supply. Do not use
as a power source for any external circuitry. Connect a
1.0µF (or greater) ceramic or plastic capacitor from TRM
to GND, as close to the device as possible.
Comparators drive interrupt source register bits 0, 1,
and 7 (Table 10) to indicate important USB OTG V
voltage levels:
•
•
•
The vbus_valid comparator sets vbus_vld to 1 if V
higher than the V
V
to determine if the B device is sinking too much current
(i.e., is not supported). The session_valid comparator
sets sess_vld to 1 if V
valid comparator threshold. This status bit indicates that
a data transfer session is valid. The session_end com-
parator sets sess_end to 1 if V
BUS
V
USB session is valid (sess_vld)
USB session has ended (sess_end)
BUS
valid status bit (vbus_vld) is used by the A device
is valid (vbus_vld)
V
V
BUS
BUS
V
V
TH-SESS_VLD
TH-SESS_END
CC
V
BUS
Level-Detection Comparators
TH-VBUS
or V
valid comparator threshold. The
BUS
BUS
Linear Regulator (TRM)
. The regulator power-supply
is higher than the session
BUS
VBUS_VLD
SESS_VLD
SESS_END
is higher than the
BUS
BUS
13
is